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CX11x, CX31x, CX710 (Earlier Than V6.03), and CX91x Series Switch Modules V100R001C10 Configuration Guide 13

The documents describe the configuration of various services supported by the CX11x&CX31x&CX91x series switch modules The description covers configuration examples and function configurations.
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Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Configuring PIM (IPv4)

Configuring PIM (IPv4)

This section describes the procedures for configuring PIM (IPv4).

Configuring PIM-SM (IPv4)

The PIM protocol implements multicast routing and data forwarding in a domain. The PIM-SM protocol is a multicast routing protocol in sparse mode. It applies to a large-scale network with sparsely-distributed group members.

Configuring PIM-SM in the ASM Model

A PIM-SM network uses the ASM model to provide multicast services for user hosts. User hosts in a multicast group can receive multicast data sent from any multicast source to this group.

Pre-configuration Tasks

Before configuring PIM-SM in the ASM model, configure a unicast routing protocol to ensure that unicast routes on the network are reachable.

Configuration Process

Mandatory procedures for configuring PIM-SM in the ASM model are as follows:

  1. Enable PIM-SM.
  2. Configure an RP.

Perform the optional configuration tasks as required.

Enabling PIM-SM

Context

It is recommended that you enable PIM-SM on all interfaces in a PIM-SM domain, so that the interfaces can establish neighbor relationships with all connected PIM devices.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    multicast routing-enable

    The IP multicast routing function is enabled.

  3. Run:

    interface interface-type interface-number

    The interface view is displayed.

  4. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  5. Run:

    pim sm

    PIM-SM is enabled.

  6. Run:

    commit

    The configuration is committed.

Configuring an RP

Context

An RP can be configured manually or elected through the BSR mechanism. Manually configuring a static RP reduces bandwidth used for frequent information exchange between the C-RPs and BSR. RP election through the BSR mechanism simplifies configuration and improves reliability of multicast forwarding because multiple C-RPs are configured.

To allow the local device to receive Auto-RP Announcement or Discovery messages from other devices, enable the listening of Auto-RP messages.

You can configure a static RP and multiple C-RPs for dynamic RP election. The static RP functions as a backup RP because it has a lower priority. Ensure that all the devices on the network have the same RP information. Inconsistent RP information may cause forwarding failures on the network.

Default Configuration

Table 8-33 lists the default configuration of the C-BSR and C-RP.

Table 8-33 Default configuration of the C-BSR and C-RP

Parameter

Default Setting

C-BSR priority

0

C-BSR hash mask length

30

BSR message fragmentation

Disabled

Multicast group policy of a static RP

No multicast group policy configured (receiving multicast data with any group address)

Multicast group policy of a C-RP

No multicast group policy configured (receiving multicast data with any group address)

C-RP priority

0

Interval for sending C-RP Announcement messages

60s

Hold time of C-RP Announcement messages

150s

Procedure

  • Configure a static RP.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      static-rp rp-address [ basic-acl-number | acl-name acl-name ] [ preferred ]

      Address of a static RP is specified.

      preferred indicates that the static RP takes precedence over a dynamic RP.

      All devices in the PIM-SM domain must be configured with the same static RP address.

    4. Run:

      commit

      The configuration is committed.

  • Configure a dynamic RP.

    1. Configure a C-BSR.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        pim

        The PIM view is displayed.

      3. Run:

        c-bsr interface-type interface-number [ hash-length [ priority ] ]

        A C-BSR is configured.

        It is recommended that you configure the C-BSR on the device that aggregates multicast data.

      4. (Optional) Run:

        bsm semantic fragmentation

        The BSR message fragmentation function is enabled.

        BSR message fragmentation is recommended because it can solve the problem faced by IP fragmentation that all fragments become unavailable due to loss of fragment information. Enable BSR message fragmentation on all devices. Otherwise, devices that do not fragment BSR messages may receive incomplete RPs.

      5. Run:

        commit

        The configuration is committed.

    2. Configure a C-RP.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        pim

        The PIM view is displayed.

      3. Run:

        c-rp interface-type interface-number [ group-policy { basic-acl-number | acl-name acl-name } | priority priority | holdtime hold-interval | advertisement-interval adv-interval ]*

        A C-RP is configured.

        It is recommended that you configure the C-RP on the device that aggregates multicast data.

      4. Run:

        commit

        The configuration is committed.

    3. (Optional) Configure a BSR boundary.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        interface interface-type interface-number

        The interface view is displayed.

      3. (Optional) On an Ethernet interface, run:

        undo portswitch

        The interface is switched to Layer 3 mode.

        By default, an Ethernet interface works in Layer 2 mode.

        If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

        If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

      4. Run:

        pim bsr-boundary [ incoming ]

        A BSR service boundary is configured.

        The BSR messages cannot pass through the BSR boundary. Therefore, it is recommended that you configure the BSR service boundary on interfaces at the edge of a PIM-SM domain.

      5. Run:

        commit

        The configuration is committed.

  • Enable listening of Auto-RP messages.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      auto-rp listening enable

      Listening of Auto-RP messages is enabled.

    4. Run:

      commit

      The configuration is committed.

(Optional) Configuring a BSR Administrative Domain

Context

To facilitate PIM domain management, a PIM network is divided into multiple BSR administrative domains and a global domain. Each BSR administrative domain maintains only one BSR that serves specified multicast groups. Multicast groups that do not belong to any BSR administrative domain are served by the global domain. A device can join only one administrative domain, so devices in each administrative domain can forward multicast data independently. Data of multicast groups in the global domain can be forwarded through devices in any administrative domain.

The maximum range of multicast groups that a BSR administrative domain can serve is 239.0.0.0 to 239.255.255.255. Multicast addresses in this range are used as private group addresses.

Procedure

  1. Enable BSR administrative domain on all devices in the PIM domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr admin-scope

      The BSR administrative domain is enabled.

    4. Run:

      commit

      The configuration is committed.

  2. Configure a BSR administrative domain boundary on an edge interface.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      multicast boundary group-address { mask | mask-length }

      The boundary of the BSR administrative domain is configured.

      Multicast packets that belong to the BSR administrative domain cannot traverse the boundary.

    5. Run:

      commit

      The configuration is committed.

  3. Configure a group address range for the C-BSR in each BSR administrative domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr group group-address { mask | mask-length } [ hash-length hash-length | priority priority ] *

      A group address range is configured for the C-BSR in each BSR administrative domain.

    4. Run:

      commit

      The configuration is committed.

  4. Configure a C-BSR in the global domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr global [ hash-length hash-length | priority priority ] *

      A C-BSR is configured for the global administrative domain.

    4. Run:

      commit

      The configuration is committed.

(Optional) Configuring SPT Switchover Conditions

Context

A high volume of multicast data traffic increases the load of an RP and may result in a fault. The DR at the group member side triggers SPT switchover to reduce the burden of the RP.

By default, a DR at the group member side immediately triggers SPT switchover after receiving the first multicast data packet. You can configure a traffic rate threshold on a DR at the group member side to trigger an SPT switchover or prevent the DR from triggering an SPT switchover.

Default Configuration

Table 8-34 lists the default configuration of SPT switchover conditions.

Table 8-34 Default configuration of SPT switchover conditions

Parameter

Default Setting

Group policy that specifies the groups to which the SPT switchover conditions apply

No group policy configured (The SPT switchover conditions apply to all multicast groups.)

Interval for checking the forwarding rate of multicast data

15s

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    spt-switch-threshold { traffic-rate | infinity } [ group-policy { basic-acl-number | acl-name acl-name } [ order order-value ] ]

    The SPT switchover condition is configured.

    traffic-rate specifies the rate threshold that triggers an SPT switchover. infinity indicates that the SPT switchover is never triggered.

  4. Run:

    timer spt-switch interval

    The interval for checking the forwarding rate of multicast data is configured.

  5. Run:

    commit

    The configuration is committed.

(Optional) Adjusting Control Parameters for Source Registering

Context

After receiving multicast data from a multicast source, the source DR encapsulates multicast data in a Register message and forwards the message to the RP. Therefore, you can adjust control parameters for source registering on the RP and source DR.

You can perform the following operations on the source DR.

  • Configure the register message suppression time. After receiving a Register-Stop message, the source DR stops sending Register messages to the RP during register suppression. The source DR forwards packets again when the register suppression time expires and it receives no more Register-Stop messages.
  • Configure the interval at which null Register messages are sent. When the timeout period for keeping the register suppression state is too long or too short, multicast data cannot be forwarded normally. Sending null Register messages during register suppression can relieve this problem.
  • Configure the source address for Register messages. The RP cannot receive Register messages from a source DR if the source address of the Register messages is not a unique IP address on the network or if the source address is filtered out by a policy configured on the RP. To enable the RP to receive Register messages from the source DR, configure a new source address for the Register messages.

You can perform the following operations on the RP.

  • Configure a policy to filter Register messages. You can specify the address range of Register messages to improve network security.
Default Configuration

Table 8-35 lists default configuration of control parameters for source registering.

Table 8-35 Default configuration of control parameters for source registering

Parameter

Default Setting

Filter policy for Register messages

No filter policy configured (receiving Register messages with any group address)

Way to calculate the checksum

Based on the entire message

Register message suppression time

60s

Interval for sending null Register messages

5s

Procedure

  • Configure control parameters for source registering on the source DR.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      register-suppression-timeout interval

      Register message suppression time is configured.

    4. Run:

      probe-interval interval

      The interval for sending null Register messages is configured.

      The value of probe-interval must be smaller than half of register-suppression-timeout.

    5. Run:

      register-packet-checksum

      The checksum is calculated based on all the contents of a Register message.

    6. Run:

      register-source interface-type interface-number

      The source address of Register messages sent from the source DR is configured.

      It is recommended that you use the IP address of a loopback interface on the source DR as the source address of Register messages.

    7. Run:

      commit

      The configuration is committed.

  • Configure control parameters for source registering on the RP.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      register-policy { advanced-acl-number | acl-name acl-name }

      A policy for filtering Register messages is configured.

    4. Run:

      commit

      The configuration is committed.

(Optional) Adjusting C-RP Control Parameters

Context

When a C-RP is configured on an interface, the C-RP periodically sends Advertisement messages to a BSR. The Advertisement messages carry the C-RP priority and the holdtime of Advertisement messages. After receiving Advertisement messages, the BSR starts the C-RP timeout timer. The timer value is set to the holdtime of Advertisement messages. Before the timer expires, the BSR collects the C-RP information in Advertisement messages into an RP-set, encapsulates the RP-set into a Bootstrap message, and advertises the Bootstrap message to all PIM devices in the PIM domain. If the BSR does not receive any Advertisement message from the C-RP after the timer expires, the BSR considers the C-RP invalid or unreachable on the network. The interval for sending Advertisement messages must be smaller than the holdtime of Advertisement messages.

You can manually configure the interval for sending Advertisement messages, C-RP priority and holdtime of Advertisement messages. To prevent C-RP spoofing, set the range of valid C-RP addresses on the BSR. Then the BSR accepts only the Advertisement messages with the source addresses in the specified range.

Procedure

  • Configure parameters on Advertisement messages on the C-RP.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-rp priority priority

      The C-RP priority is configured.

    4. Run:

      c-rp advertisement-interval interval

      The interval for sending Advertisement messages is configured.

    5. Run:

      c-rp holdtime interval

      The time period to hold the Advertisement messages received from the C-RP is configured.

    6. Run:

      commit

      The configuration is committed.

  • Configure the valid C-RP address range on the BSR.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-rp policy { advanced-acl-number | acl-name acl-name }

      The range of valid C-RP addresses and the range of groups that C-RPs serve are configured.

    4. Run:

      commit

      The configuration is committed.

(Optional) Adjusting C-BSR Control Parameters

Context

C-BSRs automatically elect a BSR in a PIM domain. At first, each C-BSR considers itself as a BSR and sends Bootstrap messages to all devices in the domain. When a C-BSR receives a Bootstrap message from another C-BSR, it compares the priority in the received Bootstrap message with its own priority. The C-BSR with a higher priority wins. If the two BSRs have the same priority, the BSR with a larger IP address is preferred. After a C-BSR is elected as the BSR, it encapsulates its own IP address and the RP-Set information into a Bootstrap message and sends the Bootstrap message in the PIM domain. The Bootstrap message contains a hash mask which is used for hash calculation in C-RP election.

The BSR periodically sends a Bootstrap message to the network. When the other C-BSRs receive the Bootstrap message, they start the holdtime timer. If they do not receive any Bootstrap message from the BSR when the holdtime timer expires, they consider that the BSR fails and initiate the election of a new BSR. The interval for sending Bootstrap messages must be smaller than the holdtime of a Bootstrap message.

You can configure the C-BSR priority, the BSR hash mask length, the interval for sending Bootstrap messages, and the holdtime of Bootstrap messages. To prevent BSR spoofing, set a range of valid BSR addresses on devices, so that the devices receive messages only from the BSRs within the address range.

Default Configuration

Table 8-36 lists the default configuration of the C-BSR.

Table 8-36 Default configuration of the C-BSR

Parameter

Default Setting

Interval for sending Bootstrap messages

60s

Holdtime of Bootstrap messages

130s

Procedure

  • Configure parameters contained in a Bootstrap message for a C-BSR.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr priority priority

      The priority of the C-BSR is configured.

    4. Run:

      c-bsr hash-length priority

      The hash mask length of the C-BSR is configured.

    5. Run:

      c-bsr interval interval

      The interval for the BSR to send Bootstrap messages is configured.

    6. Run:

      c-bsr holdtime interval

      The holdtime of the Bootstrap message received from the BSR is configured.

    7. Run:

      commit

      The configuration is committed.

  • Configure a valid BSR address range on a PIM device.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      bsr-policy { basic-acl-number | acl-name acl-name }

      The range of valid BSR addresses is configured.

    4. Run:

      commit

      The configuration is committed.

Checking the Configuration

Prerequisites

After configuration of PIM-SM in ASM model is complete, you can check information about the BSR, RP, PIM interface, PIM neighbor, and PIM routing table.

Procedure

  • Run the display pim bsr-info command to check the BSR configuration.
  • Run the display pim rp-info [ group-address ] command to check the RP configuration.
  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.
  • Run the following commands to check the PIM routing table.

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Configuring PIM-SM in the SSM Model

A PIM-SM network uses the SSM model to provide specified multicast services for user hosts. User hosts in a multicast group can receive multicast data sent from the specified multicast source to this group.

Pre-configuration Tasks

Before configuring PIM-SM in the SSM model, configure a unicast routing protocol to ensure that unicast routes on the network are reachable.

Configuration Process

Enabling PIM-SM is a mandatory procedure. Configuring an SSM group policy can control the address range of SSM groups. This operation is optional.

Enabling PIM-SM

Context

It is recommended that you enable PIM-SM on all interfaces in a PIM-SM domain, so that the interfaces can establish neighbor relationships with all connected PIM devices.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    multicast routing-enable

    The IP multicast routing function is enabled.

  3. Run:

    interface interface-type interface-number

    The interface view is displayed.

  4. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  5. Run:

    pim sm

    PIM-SM is enabled.

  6. Run:

    commit

    The configuration is committed.

(Optional) Configuring an SSM Group Policy

Context

By default, the SSM group address range is 232.0.0.0/8. Sometimes, the address range of SSM groups must be limited to ensure security of multicast networks. If the addresses in the default range are insufficient, the SSM group address range needs to be expanded. You can configure an SSM group policy to control the address range of SSM groups.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    ssm-policy { basic-acl-number | acl-name acl-name }

    The SSM group address range is configured.

    Ensure that the SSM group address range of all devices in the network are the same.

  4. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisites

After configuration of PIM-SM in SSM model is complete, you can check information about the PIM interface, PIM neighbor, and PIM routing table.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.
  • Run the following commands to check the PIM routing table.

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Adjusting Multicast Source Control Parameters

You can configure the source address-based filtering rules and multicast source lifetime to improve security of packets and control traffic on networks.

Pre-configuration Tasks

Before setting the parameters for controlling a multicast source, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Context

After a PIM device receives a multicast packet from a multicast source, it starts a timer for the (S, G) entry and sets the timer to the multicast source lifetime. If the device receives a packet from the source before the timer expires, it resets the timer. If the device does not receive any multicast packet from the source within the lifetime, it considers the corresponding (S, G) entry invalid and deletes this entry. You can configure the multicast source lifetime.

To control multicast traffic or ensure data security, configure source address-based filtering policies on the device so that the device accepts only multicast data allowed by the policies.

Default Configuration

Table 8-37 lists default configuration of multicast source control parameters.

Table 8-37 Default configuration of multicast source control parameters

Parameter

Default Setting

Keepalive period of a multicast source

210s

Source address filtering policy

No policy configured (Multicast data from all sources is accepted.)

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    source-lifetime interval

    The multicast source lifetime is configured.

    Configure the source lifetime according to the number of the multicast forwarding entries used. If a large number of multicast entries are used on your network, a too short lifetime will make the multicast forwarding table incomplete. However, if the lifetime is too long, invalid entries will be retained for a long time, wasting system resources. The following table lists the recommended lifetime values for different quantities of multicast forwarding entries.

    Number of Entries

    Recommended Lifetime Value

    Within 1000

    Default value

    1000 to 2000

    1000 seconds

    2000 to 8000

    2000 seconds

    More than 8000

    4000 seconds

  4. Run:

    source-policy { acl-number | acl-name acl-name }

    A multicast source address-based filtering policy is configured.

    • If a basic ACL is specified in the command, the allowed multicast packets are specified by the source parameter in the rule configured under the basic ACL. The device forwards only the multicast packets with the source addresses allowed by the filtering policy.

    • If an advanced ACL is specified in the command, the allowed multicast packets are specified by source and destination parameters in the rule configured under the advanced ACL. The device forwards only the multicast packets with both source addresses and group addresses allowed by the filtering policy.

    • If the specified ACL contains no rule, the device does not forward multicast packets from any sources.

    • This command does not filter multicast packets that match the PIM entries generated from statically configured IGMP (S, G) entries.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

After the control parameters of a multicast source are adjusted, you can check entries in the PIM routing table.

Run the following commands to check the PIM routing table.
  • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

  • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Adjusting Control Parameters for Establishing Neighbor Relationships

PIM devices establish PIM neighbor relationships by exchanging Hello messages.

Pre-configuration Tasks

Before configuring control parameters for establishing neighbor relationships, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Configuration Process

You can configure the Hello message control parameters and neighbor filtering function in any sequence as required.

Adjusting Control Parameters for Hello Messages

Context

PIM devices send Hello messages periodically to maintain PIM neighbor relationships. When a PIM device receives a Hello message from a neighbor, the PIM device starts the timer and sets the timer to the holdtime of Hello messages. If the PIM device does not receive a new Hello message from the neighbor within the holdtime, it considers the neighbor invalid or unreachable. Therefore, the interval for a PIM device to send Hello messages must be smaller than the holdtime of Hello messages.

The interval for sending Hello messages and the holdtime of Hello messages can be set either globally or on an interface. If you configure the two parameters in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-38 lists default configuration of control parameters for Hello messages.

Table 8-38 Default configuration of control parameters for Hello messages

Parameter

Default Setting

Interval for sending Hello messages

30s

Holdtime of Hello messages

105s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      timer hello interval

      The interval for sending Hello messages is configured.

    4. Run:

      hello-option holdtime interval

      The holdtime of Hello messages is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      pim timer hello interval

      The interval for sending Hello messages is configured.

    5. Run:

      pim hello-option holdtime interval

      The holdtime of Hello messages is configured.

    6. Run:

      commit

      The configuration is committed.

Configuring PIM Neighbor Filtering

Context

The switch modules supports different neighbor filtering policies to ensure secure and effective multicast transmission in a PIM-SM domain. You can perform the following operations to filter neighbors:
  • Configure a valid neighbor address range to prevent unauthorized neighbors from connecting to the network.
  • Configure the switch modules to reject Hello messages without Generation IDs so that switch modules connects to normally working PIM neighbors.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  4. Run:

    pim neighbor-policy { basic-acl-number | acl-name acl-name }

    The range of valid neighbor addresses is configured.

    • If the IP address of a PIM neighbor that has established a neighbor relationship with the switch modules is not in the configured range of valid neighbor addresses, the switch modules will no longer receive Hello messages from this PIM neighbor. When the holdtime of Hello messages expires, the neighbor relationship between the PIM device and the switch modules is terminated.

  5. Run:

    pim require-genid

    The device is configured to receive only Hello messages that contain Generation IDs.

  6. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisites

After the control parameters for establishing the neighbor relationship are adjusted, you can check information about the PIM interface and the PIM neighbor.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.

Adjusting Control Parameters for DR Election

PIM devices exchange Hello messages to elect a DR, which is responsible for sending protocol packets at the source side or the group member side.

Pre-configuration Tasks

Before configuring control parameters for DR election, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Configuration Process

You can configure the priority for DR election and DR switchover delay in any sequence as required.

Configuring the DR Priority

Context

The shared network segment where a multicast source or group member resides is usually connected to multiple PIM devices. PIM devices exchange Hello messages to elect a DR on the network segment, which is the unique sender of multicast packets. The DR priorities carried in Hello messages are compared at first. The device with the highest DR priority wins (A greater value indicates a higher priority). If PIM devices have the same DR priority or at least one PIM device does not support Hello messages carrying the DR priority, the PIM device with the largest IP address wins.

The DR priority can be configured globally or on an interface. If you configure the DR priority in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-39 lists the default configuration of the DR priority.

Table 8-39 Default configuration of the DR priority

Parameter

Default Setting

DR priority

1

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      hello-option dr-priority priority

      The priority for DR election is configured.

    4. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      pim hello-option dr-priority priority

      The priority for DR election is configured.

    5. Run:

      commit

      The configuration is committed.

Configuring the DR Switchover Delay

Context

When an interface on a shared network segment changes from a DR to a non-DR, PIM devices on the network segment immediately delete the related multicast forwarding entries. This causes loss of multicast data in a short period. To avoid such a situation, enable DR switching delay function and set a delay time. When the DR changes, the original multicast forwarding entries are retained within the delay time.

By default, the DR switchover delay function is not configured.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  4. Run:

    pim timer dr-switch-delay interval

    The DR switchover delay function is enabled and a delay time is configured.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisites

After the control parameters for electing a DR are adjusted, you can check information about the PIM interface and the PIM neighbor.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.

Adjusting Control Parameters for Join/Prune Messages

A multicast device sends Join messages upstream to require forwarding of multicast data, and Prune messages upstream for requiring to stop forwarding multicast data. You can configure control parameters for Join/Prune messages as required. If there is no special requirement, the default values are recommended.

Pre-configuration Tasks

Before configuring control parameters for Join/Prune messages, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Configuration Process

You can configure time related parameters for Join/Prune messages, disable Join/Prune packaging, Prune delay, and Join information filtering in any sequence as required.

Adjusting Time Related Parameters for Join/Prune Messages

Context

A multicast device sends Join messages upstream to require forwarding of multicast data, and Prune messages upstream for requiring to stop forwarding multicast data. Join information and prune information are encapsulated in Join/Prune messages. The PIM device periodically sends Join/Prune messages to an upstream device to update the forwarding state. When the upstream device receives a Join/Prune message, it starts a timer and sets the timer value to the holdtime of the Join/Prune message. If the device does not receive any Join/Prune message when the timer expires, it acts as follows:

  • If the previously received Join/Prune message is sent by a host to join a multicast group, the device stops sending multicast data to the downstream interface of the multicast group.
  • If the previously received Join/Prune message is sent to prune the downstream interface of a multicast group, the device starts to send multicast data packets to the downstream interface.

Therefore, the interval for sending Join/Prune messages must be smaller than the holdtime of a Join/Prune message.

The interval for sending Join/Prune messages and the holdtime of Join/Prune messages can be set globally or on an interface. If you configure the two parameters in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-40 lists the default configuration of time related parameters for Join/Prune messages.

Table 8-40 Default configuration of time related parameters for Join/Prune messages

Parameter

Default Setting

Interval for sending Join/Prune messages

60s

Holdtime of Join/Prune messages

210s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      timer join-prune interval

      The interval for sending Join/Prune messages is configured.

    4. Run:

      holdtime join-prune interval

      The holdtime of Join/Prune messages is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      pim timer join-prune interval

      The interval for sending Join/Prune messages is configured.

    5. Run:

      pim holdtime join-prune interval

      The holdtime of Join/Prune messages is configured.

    6. Run:

      commit

      The configuration is committed.

Disabling PIM Join/Prune Message Packaging

Context

The efficiency for sending PIM Join/Prune messages in a package is higher than that for separately sending a large number of PIM Join/Prune messages. By default, a device sends PIM Join/Prune messages in a package. Because the size of a PIM Join/Prune message package is large, devices that have poor performance cannot receive the PIM Join/Prune message package. To prevent packets from being discarded, disable the Join/Prune message packaging function.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    join-prune triggered-message-cache disable

    The real-time Join/Prune message packaging function is disabled.

  4. Run:

    commit

    The configuration is committed.

Adjusting Control Parameters for Prune Delay

Context

LAN-delay specifies the delay from the time a device receives a Prune message from a downstream interface to the time it sends the Prune message to an upstream interface. A PIM device does not prune the corresponding downstream interface immediately after it sends the Prune message. If another device still requests multicast data, it needs to send a Join message to the upstream device within this period. The period for overriding the Prune message is called override-interval. The delay from the time a PIM device receives a Prune message to the time it performs the prune action is the sum of the lan-delay and override-interval.

The lan-delay and override-interval can be configured globally or on an interface. If you configure the lan-delay and override-interval in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-41 lists the default configuration of control parameters for prune delay.

Table 8-41 Default configuration of control parameters for prune delay

Parameter

Default Setting

LAN-delay

500 ms

Override-interval

2500 ms

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      hello-option lan-delay interval

      The delay for transmitting messages in a shared network is configured.

    4. Run:

      hello-option override-interval interval

      The interval for overriding the prune action is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      pim hello-option lan-delay interval

      The delay for transmitting messages in a shared network is configured.

    5. Run:

      pim hello-option override-interval interval

      The interval for overriding the prune action is configured.

    6. Run:

      commit

      The configuration is committed.

Configuring a Join Information Filtering Policy

Context

To prevent access of unauthorized users, configure a join information filtering policy to specify a valid source address range for join information contained in Join/Prune messages.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  4. Run:

    pim join-policy { asm { basic-acl-number | acl-name acl-name } | ssm { advanced-acl-number | acl-name acl-name } | advanced-acl-number | acl-name acl-name }

    A Join information filtering policy is configured and a valid source address range is specified.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisites

After control parameters for Join/Prune messages are configured, you can check information about the PIM interface, statistics about PIM control messages, and PIM routing table.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
  • Run the following commands to check the number of sent or received PIM control messages.

    • display pim control-message counters message-type { probe | register | register-stop | crp }

    • display pim control-message counters [ message-type { assert | hello | join-prune | bsr } | interface interface-type interface-number ] *

  • Run the following commands to check the PIM routing table.

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Adjusting Assert Control Parameters

When a device receives multicast data through a downstream interface, the device knows that other upstream devices exist on this network segment. The device then sends an Assert message to participate in the election of the unique upstream device.

Pre-configuration Tasks

Before configuring assert control parameters, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Context

When multiple PIM devices on a network segment pass the Reverse Path Forwarding (RPF) check and forward multicast data to this network segment, assert election is required to ensure that only one PIM device forwards multicast data to this network segment.

PIM devices that fail the assert election disable their downstream interfaces from forwarding multicast data to this network segment. The assert loser state lasts for a period, which is called the holdtime of Assert messages. After the assert state timer times out, the devices that lost the Assert election restore pruned interfaces to the forwarding state to trigger a new round of Assert election.

The holdtime of Assert messages can be configured globally or on an interface. If you configure the holdtime of Assert messages in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-42 lists default configuration of assert control parameters.

Table 8-42 Default configuration of assert control parameters

Parameter

Default Setting

Period for holding the Assert state

180s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      holdtime assert interval

      The holdtime of Assert messages is configured.

      By default, the holdtime of Assert messages is 180 seconds.

    4. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. On an Ethernet interface, run:

      undo portswitch

      The interface is switched to Layer 3 mode.

      By default, an Ethernet interface works in Layer 2 mode.

      If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

      If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

    4. Run:

      pim holdtime assert interval

      The period for holding the Assert state is configured.

    5. Run:

      commit

      The configuration is committed.

Checking the Configuration

After assert control parameters are configured, you can check information about the PIM interface, PIM neighbor, and PIM routing table using the following commands:

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.

  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.

  • Run the following commands to check the PIM routing table.
    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Configuring PIM Anycast RP

Anycast RP configures several RPs with the same address in a PIM-SM domain and establishes peer relationships between RPs so that the multicast source can register with the closest RP and the multicast receiver can join the closest RP. This releases burdens on a single RP, implements RP backup, and optimizes multicast forwarding paths.

Context

Currently, there are two anycast implementations: MSDP for anycast RP and PIM for anycast RP. In IPv4 network deployment, choose either of the two modes. It is recommended that the two modes be not used together.

Pre-configuration Tasks

Before configuring PIM anycast RP, complete the following task:

Configuration Process

Configure anycast RP in the following sequence.

Configuring Global Anycast RP

Context

Either a static or dynamic RP can be used on the network. It is recommended that an RP be configured on loopback interfaces. The same RP address is configured on multiple switch moduless where anycast RP will be deployed.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    anycast-rp rp-address

    Anycast RP is configured.

    The anycast RP address must be the same as that of the RP address on the current network.

  4. Run:

    commit

    The configuration is committed.

Configuring Local Addresses for Anycast RPs

Context

The devices functioning as Anycast RPs are identified by the same logical address so that the RP in the PIM-SM domain is unique. However, the devices need to distinguish one another during communication, so the Anycast RP addresses cannot be used. In this situation, you need to configure the Anycast RP local address and Anycast RP peers.

After the local address is configured, the RP uses the local addresses as the source addresses of the packets when sending Register packets to Anycast RP peers.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    anycast-rp rp-address

    The Anycast RP view is displayed.

  4. Run:

    local-address local-address

    Local addresses are configured for Anycast RP.

    You are advised to use the address of the Loopback interface as the local address of the Anycast RP.

    The local address of the Anycast RP must be different from the address of the Anycast RP.

  5. Run:

    commit

    The configuration is committed.

Configuring Anycast RP Peers

Context

The devices functioning as Anycast RPs are identified by the same logical address so that the RP in the PIM-SM domain is unique. However, the devices need to distinguish one another during communication, so the Anycast RP addresses cannot be used. In this situation, you need to configure the Anycast RP local address and Anycast RP peers.

After Anycast RP peers are configured, the RP uses the peer addresses as the destination addresses of the packets when sending Register packets to Anycast RP peers.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    anycast-rp rp-address

    The Anycast RP view is displayed.

  4. Run:

    peer peer-address [ fwd-msdp-sa [ acl-number | acl-name acl-name ] ]

    Anycast RP peers are configured.

    In a PIM-SM domain, devices functioning as Anycast RP must be fully connected. Anycast RP peer relationships need to be configured between every two Anycast RPs.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

Context

After PIM for Anycast RP is configured, you can check the PIM for Anycast RP configurations.

Procedure

  • Run the display pim rp-info command to check the RP.
  • Run the following commands to check the PIM routing table.

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } | outgoing-interface { include | exclude | match } { interface-type interface-number | register | none } | mode { sm | ssm } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]

    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Configuring PIM BFD

PIM BFD can detect link status changes on a shared network segment in milliseconds, enabling PIM devices to rapidly respond to failures of PIM neighbors. This reduces the multicast service interruption time and improves reliability of multicast data transmission.

Pre-configuration Tasks

Before configuring PIM BFD, complete the following tasks:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling BFD globally using the bfd command
  • Enabling PIM-SM

Context

On a PIM network, changes of link status between PIM neighbors will restart some PIM mechanisms, such as DR election or Assert winner election. For example, when the DR on a shared network segment fails, PIM neighbors on the network segment trigger DR re-election only when the PIM neighbor relationships time out. Multicast data transmission is interrupted before a new DR is elected. The multicast service interruption time is longer than or equal to the neighbor relationship timeout interval, and is usually several seconds.

PIM BFD can detect link status changes on a shared network segment in milliseconds, enabling PIM devices to rapidly respond to failures of PIM neighbors. If a PIM BFD-capable interface does not receive any BFD packets from the DR within the detection interval, it considers that the DR has failed. Then BFD rapidly reports the session status to the route management (RM) module, which then reports the link status change to the PIM module. After receiving the notification, the PIM module triggers DR re-election immediately, without waiting for timeout of the neighbor relationship. This mechanism reduces the multicast service interruption time and improves reliability of multicast data transmission.

PIM BFD is applicable to the assert election on the shared network segment. In addition, it quickly responds to faults on the assert winner interface.

Default Configuration

Table 8-43 lists default configuration of control parameters for PIM BFD messages.

Table 8-43 Default configuration of control parameters for PIM BFD messages

Parameter

Default Setting

Minimum sending interval

1000 ms

Minimum receiving interval

1000 ms

Local detection multiplier

3

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  4. Run:

    pim bfd enable

    PIM BFD is enabled.

  5. (Optional)Run:

    pim bfd { min-tx-interval tx-value | min-rx-interval rx-value | detect-multiplier multiplier-value } *

    The parameters of PIM BFD are set.

    This operation is performed to set the minimum interval for sending the PIM BFD messages, the minimum interval for receiving the PIM BFD messages, and the local detection multiplier.

  6. Run:

    commit

    The configuration is committed.

Checking the Configuration

After PIM BFD is configured, you can run the following commands to check information about the PIM BFD session.

  • display pim bfd session statistics

  • display pim bfd session [ interface interface-type interface-number | neighbor neighbor-address ] *

Configuring PIM Silent

A device interface directly connected to hosts must have PIM enabled. When a malicious host sends a large number of forged PIM Hello messages to the interface, the device may break down. To defend against such an attack, set the state of the interface to PIM silent.

Pre-configuration Tasks

Before configuring PIM Silent, complete the following task:

  • Configuring a unicast routing protocol to ensure normal unicast routing on the network
  • Enabling PIM-SM

Context

On the access layer, the PIM protocol must be enabled on the interfaces directly connected to user hosts, so that the interfaces can establish PIM neighbor relationships to process various PIM packets. The configuration, however, brings security risks. When a host maliciously sends many PIM Hello messages, the device may break down.

To prevent the preceding case, you can set the state of the device interface to PIM silent. When the interface is in PIM silent state, the interface is disabled from receiving and forwarding any PIM packet. All PIM neighbors and PIM state machines on the interface are deleted. The interface functions as the static DR and immediately takes effect. The PIM silent function does not affect the IGMP function on the interface.

PIM client takes effect on an interface only when the interface is directly connected to a user network segment and when the network segment is connected only to this PIM device.

  • After you configure PIM silent on an interface, the interface no longer receives or sends any PIM packets and other PIM functions on the interface become invalid. Confirm your action before configuring this function.

  • If a user network segment is connected to multiple devices and PIM silent is enabled on interfaces of multiple devices, the interfaces become static DRs. This results in multicast faults.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. On an Ethernet interface, run:

    undo portswitch

    The interface is switched to Layer 3 mode.

    By default, an Ethernet interface works in Layer 2 mode.

    If an Ethernet interface already has Layer 2 configuration, this command fails to be executed on the interface. Before running this command on the interface, delete all the Layer 2 configuration of the interface.

    If many Ethernet interfaces need to be switched to Layer 3 mode, run the undo portswitch batch interface-type { interface-number1 [ to interface-number2 ] } &<1-10> command in the system view to switch these interfaces to Layer 3 mode in batches.

  4. Run:

    pim silent

    The PIM silent function is enabled.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

After PIM silent is configured, you can check information about the PIM interface.

Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.

Configuring Bidir-PIM (IPv4)

The IPv4 Bidirectional Protocol Independent Multicast (Bidir-PIM) protocol implements bidirectional multicast routing and data forwarding in an IPv4 PIM domain.

Configuring Basic Bidir-PIM Functions

Basic Bidir-PIM functions allow the switch modules to provide the Bidir-PIM service for hosts. A host can send multicast data to other hosts in the same multicast group as a multicast source and receive multicast data from other hosts as a receiver.

Pre-configuration Tasks

Before configuring basic Bidir-PIM functions, configure a unicast routing protocol to provide reachable routes on the network.

Configuration Process

The following configuration tasks are mandatory:

  1. Enabling Bidir-PIM
  2. Configuring an RP

The tasks of configuring a BSR administrative domain, adjusting C-RP parameters, and adjusting C-BSR parameters are optional.

Enabling Bidir-PIM

Context

Enabling Bidir-PIM globally is the prerequisite for configuring other Bidir-PIM parameters.

Bidir-PIM inherits the neighbor discovery mechanism of PIM-SM to reduce protocol complexity. Therefore, interfaces on a Bidir-PIM network must run PIM-SM to set up PIM neighbor relationships.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    multicast routing-enable

    IP multicast routing is enabled.

  3. Run:

    pim

    The PIM view is displayed.

  4. Run:

    bidir-pim

    Bidir-PIM is enabled.

    A multicast network does not allow routes that are destined for the same group address and generated by different PIM protocols. Therefore, when you enable Bidir-PIM , the system displays a message telling you that some multicast routes may be deleted. Determine whether multicast services will be affected if multicast routing information is deleted.

  5. Run:

    quit

    Quit the PIM view.

  6. Run:

    interface interface-type interface-number

    The interface view is displayed.

  7. Run:

    pim sm

    PIM-SM is enabled.

  8. Run:

    commit

    The configuration is committed.

Configuring an RP

Context

Like PIM-SM, Bidir-PIM also requires a rendezvous point (RP) on the network to forward multicast data as a transit device. When configuring an RP for Bidir-PIM, specify the bidir keyword in the configuration command to specify that the RP serves Bidir-PIM.

An RP can be configured manually or elected through the BSR mechanism. Manually configuring a static RP reduces bandwidth used for frequent information exchange between the C-RPs and BSR. RP election through the BSR mechanism simplifies configuration and improves reliability of multicast forwarding because multiple C-RPs are configured.

To allow the local device to receive Auto-RP Announcement or Discovery messages from other devices, enable listening of Auto-RP messages.

You can configure a static RP and multiple C-RPs for dynamic RP election. The static RP functions as a backup RP because it has a lower priority. Ensure that all the devices on the network have the same RP information. Inconsistent RP information may cause forwarding failures on the network.

Default Configuration

Table 8-44 lists the default configuration of C-BSR and C-RP parameters.

Table 8-44 Default configuration of C-BSR and C-RP parameters

Parameter

Default Setting

C-BSR priority

0

C-BSR hash mask length

30

BSR message fragmentation

Disabled

Multicast group policy of a static RP

No multicast group policy configured (receiving multicast data with any group address)

Multicast group policy of a C-RP

No multicast group policy configured (receiving multicast data with any group address)

C-RP priority

0

Interval for sending C-RP Announcement messages

60s

Hold time of C-RP Announcement messages

150s

Procedure

  • Configure a static RP.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      static-rp rp-address [ basic-acl-number | acl-name acl-name ] [ preferred ] bidir

      A static RP address is specified, and the RP is configured to serve Bidir-PIM.

      The preferred keyword indicates that the static RP takes precedence over a dynamic RP.

      All devices in a PIM domain must be configured with the same static RP address.

    4. Run:

      commit

      The configuration is committed.

  • Configure a dynamic RP.

    1. Configure a C-BSR.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        pim

        The PIM view is displayed.

      3. Run:

        c-bsr interface-type interface-number [ hash-length [ priority ] ]

        A C-BSR is configured.

        It is recommended that you configure the C-BSR on the device that aggregates multicast data.

      4. (Optional) Run:

        bsm semantic fragmentation

        The BSR message fragmentation function is enabled.

        BSR message fragmentation is recommended because it can solve the problem faced by IP fragmentation that all fragments become unavailable due to loss of fragment information. Enable BSR message fragmentation on all devices. Otherwise, devices that do not fragment BSR messages may receive incomplete RPs.

      5. Run:

        commit

        The configuration is committed.

    2. Configure a C-RP.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        pim

        The PIM view is displayed.

      3. Run:

        c-rp interface-type interface-number [ group-policy { basic-acl-number | acl-name acl-name } | priority priority | holdtime hold-interval | advertisement-interval adv-interval ]* bidir

        A C-RP interface is specified and configured to serve Bidir-PIM.

        It is recommended that you configure the C-RP on the device that aggregates multicast data.

      4. Run:

        commit

        The configuration is committed.

    3. (Optional) Configure a BSR boundary.

      1. Run:

        system-view

        The system view is displayed.

      2. Run:

        interface interface-type interface-number

        The interface view is displayed.

      3. Run:

        pim bsr-boundary [ incoming ]

        A BSR service boundary is configured.

        The BSR messages cannot pass through the BSR boundary. Therefore, it is recommended that you configure the BSR service boundary on interfaces at the edge of a PIM domain.

      4. Run:

        commit

        The configuration is committed.

  • Enable listening of Auto-RP messages.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      auto-rp listening enable

      Listening of Auto-RP messages is enabled.

    4. Run:

      commit

      The configuration is committed.

(Optional) Configuring a BSR Administrative Domain

Context

To facilitate PIM domain management, a PIM network is divided into multiple BSR administrative domains and a global domain. Each BSR administrative domain maintains only one BSR that serves specified multicast groups. Multicast groups that do not belong to any BSR administrative domain are served by the global domain. A device can join only one administrative domain, so devices in each administrative domain can forward multicast data independently. Data of multicast groups in the global domain can be forwarded through devices in any administrative domain.

The maximum range of multicast groups that a BSR administrative domain can serve is 239.0.0.0 to 239.255.255.255. Multicast addresses in this range are used as private group addresses.

Procedure

  1. Enable BSR administrative domain on all devices in the PIM domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr admin-scope

      The BSR administrative domain is enabled.

    4. Run:

      commit

      The configuration is committed.

  2. Configure a BSR administrative domain boundary on an edge interface.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      multicast boundary group-address { mask | mask-length }

      The boundary of the BSR administrative domain is configured.

      Multicast packets that belong to the BSR administrative domain cannot traverse the boundary.

    4. Run:

      commit

      The configuration is committed.

  3. Configure a group address range for the C-BSR in each BSR administrative domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr group group-address { mask | mask-length } [ hash-length hash-length | priority priority ] *

      A group address range is configured for the C-BSR in each BSR administrative domain.

    4. Run:

      commit

      The configuration is committed.

  4. Configure a C-BSR in the global domain.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr global [ hash-length hash-length | priority priority ] *

      A C-BSR is configured for the global administrative domain.

    4. Run:

      commit

      The configuration is committed.

(Optional) Adjusting C-RP Control Parameters

Context

When a C-RP is configured on an interface, the C-RP periodically sends Advertisement messages to a BSR. The Advertisement messages carry the C-RP priority and the holdtime of Advertisement messages. After receiving Advertisement messages, the BSR starts the C-RP timeout timer. The timer value is set to the holdtime of Advertisement messages. Before the timer expires, the BSR collects the C-RP information in Advertisement messages into an RP-set, encapsulates the RP-set into a Bootstrap message, and advertises the Bootstrap message to all PIM devices in the PIM domain. If the BSR does not receive any Advertisement message from the C-RP after the timer expires, the BSR considers the C-RP invalid or unreachable on the network. The interval for sending Advertisement messages must be smaller than the holdtime of Advertisement messages.

You can manually configure the interval for sending Advertisement messages, C-RP priority and holdtime of Advertisement messages. To prevent C-RP spoofing, set the range of valid C-RP addresses on the BSR. Then the BSR accepts only the Advertisement messages with the source addresses in the specified range.

Procedure

  • Configure parameters on Advertisement messages on the C-RP.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-rp priority priority

      The C-RP priority is configured.

    4. Run:

      c-rp advertisement-interval interval

      The interval for sending Advertisement messages is configured.

    5. Run:

      c-rp holdtime interval

      The time period to hold the Advertisement messages received from the C-RP is configured.

    6. Run:

      commit

      The configuration is committed.

  • Configure the valid C-RP address range on the BSR.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-rp policy { advanced-acl-number | acl-name acl-name }

      The range of valid C-RP addresses and the range of groups that C-RPs serve are configured.

    4. Run:

      commit

      The configuration is committed.

(Optional) Adjusting C-BSR Control Parameters

Context

C-BSRs automatically elect a BSR in a PIM domain. At first, each C-BSR considers itself as a BSR and sends Bootstrap messages to all devices in the domain. When a C-BSR receives a Bootstrap message from another C-BSR, it compares the priority in the received Bootstrap message with its own priority. The C-BSR with a higher priority wins. If the two BSRs have the same priority, the BSR with a larger IP address is preferred. After a C-BSR is elected as the BSR, it encapsulates its own IP address and the RP-Set information into a Bootstrap message and sends the Bootstrap message in the PIM domain. The Bootstrap message contains a hash mask which is used for hash calculation in C-RP election.

The BSR periodically sends a Bootstrap message to the network. When the other C-BSRs receive the Bootstrap message, they start the holdtime timer. If they do not receive any Bootstrap message from the BSR when the holdtime timer expires, they consider that the BSR fails and initiate the election of a new BSR. The interval for sending Bootstrap messages must be smaller than the holdtime of a Bootstrap message.

You can configure the C-BSR priority, the BSR hash mask length, the interval for sending Bootstrap messages, and the holdtime of Bootstrap messages. To prevent BSR spoofing, set a range of valid BSR addresses on devices, so that the devices receive messages only from the BSRs within the address range.

Default Configuration

Table 8-45 lists the default configuration of the C-BSR.

Table 8-45 Default configuration of the C-BSR

Parameter

Default Setting

Interval for sending Bootstrap messages

60s

Holdtime of Bootstrap messages

130s

Procedure

  • Configure parameters contained in a Bootstrap message for a C-BSR.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      c-bsr priority priority

      The priority of the C-BSR is configured.

    4. Run:

      c-bsr hash-length priority

      The hash mask length of the C-BSR is configured.

    5. Run:

      c-bsr interval interval

      The interval for the BSR to send Bootstrap messages is configured.

    6. Run:

      c-bsr holdtime interval

      The holdtime of the Bootstrap message received from the BSR is configured.

    7. Run:

      commit

      The configuration is committed.

  • Configure a valid BSR address range on a PIM device.
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      bsr-policy { basic-acl-number | acl-name acl-name }

      The range of valid BSR addresses is configured.

    4. Run:

      commit

      The configuration is committed.

Checking the Configuration

Prerequisite

After basic Bidir-PIM functions are configured, you can check information about the BSR, RP, PIM interfaces, PIM neighbors, and PIM routing table.

Procedure

  • Run the display pim bsr-info command to check BSR information.
  • Run the display pim rp-info [ group-address ] command to check RP information.
  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on interfaces.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check PIM neighbor information.
  • Run either of the following commands to check PIM routing information:

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] ] { rpf-interface interface-type interface-number | mode bidir } * [ outgoing-interface { include | exclude | match } { interface-type interface-number | none } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]
    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Adjusting Multicast Source Control Parameters

You can configure the source address-based filtering rules and multicast source lifetime to improve security of packets and control traffic on networks.

Pre-configuration Tasks

Before setting the parameters for controlling a multicast source, complete the following tasks:

Context

After a PIM device receives a multicast packet sent to group G, it starts a timer for the (*, G) entry and sets the timer to the multicast source lifetime. If the device receives a packet sent to the group before the timer expires, it resets the timer. If the device does not receive any multicast packet sent to the group within the lifetime, it considers the corresponding (*, G) entry invalid and deletes this entry. You can configure the multicast source lifetime.

To control multicast traffic or ensure data security, configure source address-based filtering policies on the device so that the device accepts only multicast data allowed by the policies.

Default Configuration

Table 8-46 lists default configuration of multicast source control parameters.

Table 8-46 Default configuration of multicast source control parameters

Parameter

Default Setting

Keepalive period of a multicast source

210s

Source address filtering policy

No policy configured (Multicast data from all sources is accepted.)

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    source-lifetime interval

    The multicast source lifetime is configured.

    Configure the source lifetime according to the number of the multicast forwarding entries used. If a large number of multicast entries are used on your network, a too short lifetime will make the multicast forwarding table incomplete. However, if the lifetime is too long, invalid entries will be retained for a long time, wasting system resources. The following table lists the recommended lifetime values for different quantities of multicast forwarding entries.

    Number of Entries

    Recommended Lifetime Value

    Within 1000

    Default value

    1000 to 2000

    1000 seconds

    2000 to 8000

    2000 seconds

    More than 8000

    4000 seconds

  4. Run:

    source-policy { acl-number | acl-name acl-name }

    A multicast source address-based filtering policy is configured.

    • If a basic ACL is specified in the command, the allowed multicast packets are specified by the source parameter in the rule configured under the basic ACL. The device forwards only the multicast packets with the source addresses allowed by the filtering policy.

    • If an advanced ACL is specified in the command, the allowed multicast packets are specified by source and destination parameters in the rule configured under the advanced ACL. The device forwards only the multicast packets with both source addresses and group addresses allowed by the filtering policy.

    • If the specified ACL contains no rule, the device does not forward multicast packets from any sources.

    • This command does not filter multicast packets that match the PIM entries generated from statically configured IGMP (*, G) entries.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

After the control parameters of a multicast source are adjusted, you can check entries in the PIM routing table.

Run the following commands to check the PIM routing table.
  • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] ] { rpf-interface interface-type interface-number | mode bidir } * [ outgoing-interface { include | exclude | match } { interface-type interface-number | none } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]
  • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Adjusting Neighbor Control Parameters

PIM devices establish PIM neighbor relationships by exchanging Hello messages.

Pre-configuration Tasks

Before configuring neighbor control parameters, complete the following tasks:

Configuration Process

You can configure the Hello message control parameters and neighbor filtering function in either sequence.

Adjusting Control Parameters for Hello Messages

Context

PIM devices send Hello messages periodically to maintain PIM neighbor relationships. When a PIM device receives a Hello message from a neighbor, the PIM device starts the timer and sets the timer to the holdtime of Hello messages. If the PIM device does not receive a new Hello message from the neighbor within the holdtime, it considers the neighbor invalid or unreachable. Therefore, the interval for a PIM device to send Hello messages must be smaller than the holdtime of Hello messages.

The interval for sending Hello messages and the holdtime of Hello messages can be set either globally or on an interface. If you configure the two parameters in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-47 lists default configuration of control parameters for Hello messages.

Table 8-47 Default configuration of control parameters for Hello messages

Parameter

Default Setting

Interval for sending Hello messages

30s

Holdtime of Hello messages

105s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      timer hello interval

      The interval for sending Hello messages is configured.

    4. Run:

      hello-option holdtime interval

      The holdtime of Hello messages is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim timer hello interval

      The interval for sending Hello messages is configured.

    4. Run:

      pim hello-option holdtime interval

      The holdtime of Hello messages is configured.

    5. Run:

      commit

      The configuration is committed.

Configuring PIM Neighbor Filtering

Context

The switch modules supports neighbor filtering policies to ensure secure and effective multicast transmission in a PIM domain. You can perform the following operations to filter neighbors:
  • Configure a valid neighbor address range to prevent unauthorized neighbors from connecting to the network.
  • Configure the switch modules to reject Hello messages without Generation IDs so that switch modules connects to normally working PIM neighbors.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. Run:

    pim neighbor-policy { basic-acl-number | acl-name acl-name }

    The range of valid neighbor addresses is configured.

    If the IP address of a PIM neighbor that has established a neighbor relationship with the switch modules is not in the configured range of valid neighbor addresses, the switch modules will no longer receive Hello messages from this PIM neighbor. When the holdtime of Hello messages expires, the neighbor relationship between the PIM device and the switch modules is terminated.

  4. Run:

    pim require-genid

    The device is configured to receive only Hello messages that contain Generation IDs.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisite

After the neighbor control parameters are adjusted, you can check information about PIM interfaces and PIM neighbors.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on interfaces.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check PIM neighbor information.

Adjusting DF Election Control Parameters

After PIM devices obtain RP information, they start a DF election on the shared network segment.

Pre-configuration Tasks

Before configuring DF election control parameters, complete the following tasks:

Configuration Process

You can configure the interval between Offer messages, interval between Backoff messages, and DF election robustness variable in any sequence.

Each DF election control parameter must be set to the same value on a shared network segment. Otherwise, the DF election may fail.

Configuring the Interval Between Offer Messages

Context

Devices on a Bidir-PIM shared network segment exchange Offer messages for designated forwarder (DF) election. When a device obtains RP information, it sends an Offer message to the shared network segment and starts a timer, with the value set to the configured interval between Offer messages. Before the timer expires:

  • If the device receives an Offer message carrying a better routing information to the RP, the device stops sending Offer messages.
  • If the device receives no Offer message or receives Offer messages carrying inferior routing information to the RP, the device resets the timer when the timer expires and continues sending Offer messages.

The interval between Offer messages can be configured in the PIM view or interface view. If you configure this parameter in both the PIM view and interface view, the configuration in the interface view takes effect.

Default Configuration

Table 8-48 provides the default interval between Offer messages.

Table 8-48 Default interval between Offer messages

Parameter

Default Setting

Interval between Offer messages

100 ms

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      offer-interval interval

      The interval between Offer messages is set.

    4. Run:

      commit

      The configuration is committed.

  • Interface configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim offer-interval interval

      The interval between Offer messages is set.

    4. Run:

      commit

      The configuration is committed.

Configuring the Interval Between Backoff Messages

Context

On a Bidir PIM network, the elected designated forwarder (DF) sends a Backoff message when it receives a superior Offer message. If the DF does not receive any Offer within the interval for sending the next Backoff message, it sends a Pass message to notify all the multicast devices that a new DF appears.

The interval between Backoff messages can be configured in the PIM view or interface view. If you configure this parameter in both the PIM view and interface view, the configuration in the interface view takes effect.

Default Configuration

Table 8-49 provides the default interval between Backoff messages.

Table 8-49 Default interval between Backoff messages

Parameter

Default Setting

Interval between Backoff messages

1s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      backoff-interval interval

      The interval between Backoff messages is configured.

    4. Run:

      commit

      The configuration is committed.

  • Interface configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim backoff-interval interval

      The interval between Backoff messages is configured.

    4. Run:

      commit

      The configuration is committed.

Configuring the DF Election Robustness Variable

Context

Devices on a Bidir-PIM shared network segment exchange Offer messages for designated forwarder (DF) election. The DF election robustness variable is used in a DF election in the following way:

  • If a device does not receive any Offer message from other devices after sending Offer messages robustness variable times, it considers itself as the DF.
  • If the device receives an Offer message from a neighbor with a smaller route metric to the RP, it stops participating in the DF election for a period (Time period = Robustness variable x Interval between Offer messages). This suppression period gives the neighbor a chance to be elected as the DF.
  • If the DF's route metric to the RP address increases, the DF sends Win messages at variable intervals to announce the new metric, for robustness variable times. If a device has a better route metric than the DF's, the device responds with an Offer message to trigger a new DF election.

The DF election robustness variable can be configured in the PIM view or interface view. If you configure this parameter in both the PIM view and interface view, the configuration in the interface view takes effect.

Default Configuration

Table 8-50 provides the default DF election robustness variable.

Table 8-50 Default DF election robustness variable

Parameter

Default Setting

DF election robustness variable

3

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      election-robust-count robust-value

      The DF election robustness variable is configured.

    4. Run:

      commit

      The configuration is committed.

  • Interface configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim election-robust-count robust-value

      The DF election robustness variable is configured.

    4. Run:

      commit

      The configuration is committed.

Checking the Configuration

Prerequisite

After configuring DF election control parameters, you can run the following commands to check information about PIM interfaces, PIM neighbors, and DFs.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on interfaces.
  • Run the display pim neighbor [ neighbor-address | interface interface-type interface-number | verbose ] * command to check information about PIM neighbors.
  • Run the display pim df-info [ rp rp-address | interface interface-type interface-number | verbose ] * command to check information about DFs for an RP.

Adjusting Control Parameters for Join/Prune Messages

A multicast device sends Join messages upstream to require forwarding of multicast data, and Prune messages upstream for requiring to stop forwarding multicast data. You can configure control parameters for Join/Prune messages as required. If there is no special requirement, the default values are recommended.

Pre-configuration Tasks

Before configuring control parameters for Join/Prune messages, complete the following tasks:

Configuration Process

You can configure time related parameters for Join/Prune messages, disable Join/Prune packaging, set the Prune delay time, and configure Join information filtering in any sequence as required.

Adjusting Time Related Parameters for Join/Prune Messages

Context

A PIM device sends Join messages upstream to require forwarding of multicast data, and Prune messages upstream for requiring to stop forwarding multicast data. Join information and prune information are encapsulated in Join/Prune messages. The PIM device periodically sends Join/Prune messages to an upstream device to update the forwarding state. When the upstream device receives a Join/Prune message, it starts a timer and sets the timer value to the holdtime of the Join/Prune message. If the device does not receive any Join/Prune message when the timer expires, it acts as follows:

  • If the previously received Join/Prune message is sent by a host to join a multicast group, the device stops sending multicast data to the downstream interface of the multicast group.
  • If the previously received Join/Prune message is sent to prune the downstream interface of a multicast group, the device starts to send multicast data packets to the downstream interface.

Therefore, the interval for sending Join/Prune messages must be smaller than the holdtime of a Join/Prune message.

The interval for sending Join/Prune messages and the holdtime of Join/Prune messages can be set globally or on an interface. If you configure the two parameters in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-51 lists the default configuration of time related parameters for Join/Prune messages.

Table 8-51 Default configuration of time related parameters for Join/Prune messages

Parameter

Default Setting

Interval for sending Join/Prune messages

60s

Holdtime of Join/Prune messages

210s

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      timer join-prune interval

      The interval for sending Join/Prune messages is configured.

    4. Run:

      holdtime join-prune interval

      The holdtime of Join/Prune messages is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim timer join-prune interval

      The interval for sending Join/Prune messages is configured.

    4. Run:

      pim holdtime join-prune interval

      The holdtime of Join/Prune messages is configured.

    5. Run:

      commit

      The configuration is committed.

Disabling PIM Join/Prune Message Packaging

Context

The efficiency for sending PIM Join/Prune messages in a package is higher than that for separately sending a large number of PIM Join/Prune messages. By default, a device sends PIM Join/Prune messages in a package. Because the size of a PIM Join/Prune message package is large, devices that have poor performance cannot receive the PIM Join/Prune message package. To prevent packets from being discarded, disable the Join/Prune message packaging function.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    pim

    The PIM view is displayed.

  3. Run:

    join-prune triggered-message-cache disable

    The real-time Join/Prune message packaging function is disabled.

  4. Run:

    commit

    The configuration is committed.

Adjusting Control Parameters for Prune Delay

Context

LAN-delay specifies the delay from the time a device receives a Prune message from a downstream interface to the time it sends the Prune message to an upstream interface. A PIM device does not prune the corresponding downstream interface immediately after it sends the Prune message. If another device still requests multicast data, it needs to send a Join message to the upstream device within this period. The period for overriding the Prune message is called override-interval. The delay from the time a PIM device receives a Prune message to the time it performs the prune action is the sum of the lan-delay and override-interval.

The lan-delay and override-interval can be configured globally or on an interface. If you configure the lan-delay and override-interval in the global PIM view and in the interface view simultaneously, the configuration in the interface view takes effect.

Default Configuration

Table 8-52 lists the default configuration of control parameters for prune delay.

Table 8-52 Default configuration of control parameters for prune delay

Parameter

Default Setting

LAN-delay

500 ms

Override-interval

2500 ms

Procedure

  • Global configuration
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      pim

      The PIM view is displayed.

    3. Run:

      hello-option lan-delay interval

      The delay for transmitting messages in a shared network is configured.

    4. Run:

      hello-option override-interval interval

      The interval for overriding the prune action is configured.

    5. Run:

      commit

      The configuration is committed.

  • Configuration on an interface
    1. Run:

      system-view

      The system view is displayed.

    2. Run:

      interface interface-type interface-number

      The interface view is displayed.

    3. Run:

      pim hello-option lan-delay interval

      The delay for transmitting messages in a shared network is configured.

    4. Run:

      pim hello-option override-interval interval

      The interval for overriding the prune action is configured.

    5. Run:

      commit

      The configuration is committed.

Configuring a Join Information Filtering Policy

Context

To prevent access of unauthorized users, configure a join information filtering policy to specify a valid source address range for join information contained in Join/Prune messages.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. Run:

    pim join-policy { asm { basic-acl-number | acl-name acl-name } | ssm { advanced-acl-number | acl-name acl-name } | advanced-acl-number | acl-name acl-name }

    A Join information filtering policy is configured and a valid source address range is specified.

  4. Run:

    commit

    The configuration is committed.

Checking the Configuration

Prerequisite

After configuring Join/Prune message control parameters, you can run the following commands to check information about PIM interfaces, statistics about PIM control messages, and PIM routing table.

Procedure

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on interfaces.
  • Run the display pim control-message counters [ message-type { assert | hello | join-prune | bsr } | interface interface-type interface-number ] * command to check the number of PIM control messages sent and received by a PIM device.
  • Run either of the following commands to check PIM routing information:

    • display pim routing-table [ group-address [ mask { group-mask-length | group-mask } ] ] { rpf-interface interface-type interface-number | mode bidir } * [ outgoing-interface { include | exclude | match } { interface-type interface-number | none } | flags flag-value | fsm ] * [ outgoing-interface-number [ number ] ]
    • display pim routing-table brief [ group-address [ mask { group-mask-length | group-mask } ] | source-address [ mask { source-mask-length | source-mask } ] | incoming-interface { interface-type interface-number | register } ] *

Configuring PIM BFD

After detecting a fault on the peer, BFD immediately instructs the PIM module to trigger a new DF election rather than waits until the neighbor relationship times out. This shortens multicast forwarding interruption time and improves reliability of multicast data transmission.

Pre-configuration Tasks

Before configuring PIM BFD, complete the following tasks:

Context

Normally, if the current DF is faulty on the shared network segment, other PIM neighbors participate in DF election after the neighbor relationship times out. Consequently, multicast data transmission is interrupted. The interruption period, usually in seconds, is longer than or equal to the timeout interval of the neighbor relationship.

BFD can detect faults in milliseconds. BFD is used to detect the status of PIM neighbors on the shared network segment. When detecting a fault on the peer device, BFD reports the fault to the PIM module. The PIM module triggers a new DF election immediately instead of waiting the timeout of the neighbor relationship. This shortens the interruption time of multicast data transmission and improves reliability of the multicast network.

Default Configuration

Table 8-53 lists default configuration of control parameters for PIM BFD messages.

Table 8-53 Default configuration of control parameters for PIM BFD messages

Parameter

Default Setting

Minimum sending interval

1000 ms

Minimum receiving interval

1000 ms

Local detection multiplier

3

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. Run:

    pim bfd enable

    PIM BFD is enabled.

  4. (Optional)Run:

    pim bfd { min-tx-interval tx-value | min-rx-interval rx-value | detect-multiplier multiplier-value } *

    This operation is performed to set the minimum interval for sending the PIM BFD messages, the minimum interval for receiving the PIM BFD messages, and the local detection multiplier.

  5. Run:

    commit

    The configuration is committed.

Checking the Configuration

After PIM BFD is configured, you can run the following commands to check information about the PIM BFD session.

  • display pim bfd session statistics

  • display pim bfd session [ interface interface-type interface-number | neighbor neighbor-address ] *

Configuring PIM Silent

A device interface directly connected to hosts must have PIM enabled. When a malicious host sends a large number of forged PIM Hello messages to the interface, the device may break down. To defend against such an attack, set the state of the interface to PIM silent.

Pre-configuration Tasks

Before configuring PIM Silent, complete the following task:

Context

On the access layer, when the interface directly connected to a device is enabled with the PIM protocol, a PIM neighbor relationship can be established on this interface to process various PIM packets. The configuration, however, has the security risks. To be specific, when a host maliciously sends PIM Hello messages, the device may break down.

To prevent the preceding case, you can set the state of the device interface to PIM silent. When the interface is in PIM silent state, the interface is disabled from receiving and forwarding any PIM packet. All PIM neighbors and PIM state machines on the interface are deleted. The PIM silent function does not affect the IGMP function on the interface.

PIM client takes effect on an interface only when the interface is directly connected to a user network segment and when the network segment is connected only to this PIM device.

After you configure PIM silent on an interface, the interface no longer receives or sends any PIM packets and other PIM functions on the interface become invalid. Confirm your action before configuring this function.

Procedure

  1. Run:

    system-view

    The system view is displayed.

  2. Run:

    interface interface-type interface-number

    The interface view is displayed.

  3. Run:

    pim silent

    The PIM silent function is enabled.

  4. Run:

    commit

    The configuration is committed.

Checking the Configuration

After PIM silent is configured, you can check information about the PIM interface.

  • Run the display pim interface [ interface-type interface-number | up | down ] [ verbose ] command to check PIM information on an interface.
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Updated: 2019-12-13

Document ID: EDOC1000041694

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