Configuring ERPSv2
When there is no faulty link on a ring network, Ethernet Ring Protection Switching (ERPS) can eliminate loops on the network. When a link fails on the ring network, ERPS can immediately restore communication between nodes on the network. ERPSv2, compatible with ERPSv1, supports multi-ring topologies, in addition to ERPSv1 functions such as single ring topologies and multi-instance.
- Creating an ERPS Ring
- Configuring the Control VLAN
- Configuring an ERP Instance and Activating the Mapping Between the ERP Instance and VLAN
- Adding a Layer 2 Port to an ERPS Ring and Configuring the Port Role
- Configuring the Topology Change Notification Function
- (Optional) Configuring ERPS Protection Switching
- (Optional) Configuring Timers in an ERPS Ring
- Verifying the ERPS Configuration
Creating an ERPS Ring
Context
ERPS works for ERPS rings. An ERPS ring consists of interconnected Layer 2 switching devices configured with the same control VLAN and data VLAN. Before configuring other ERPS functions, configure an ERPS ring.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
An ERPS ring is created and the ERPS ring view is displayed.
By default, an ERPS ring configured using the erps ring ring-id command is a major ring.
- Run version v2
ERPSv2 is specified.
By default, ERPSv1 is used.
Before specifying ERPSv1 for an ERPSv2-enabled device, delete all ERPS configurations that ERPSv1 does not support.
- (Optional) Run sub-ring
The ERPS ring is configured as a sub-ring.
By default, an ERPS ring is a major ring. Major rings are closed, and sub-rings are open. This step is performed only when an existing ERPS ring needs to be used as a sub-ring.
An ERPS ring that has a port cannot be configured as a sub-ring. Before configuring an ERPS ring that has a port as a sub-ring, run the undo erps ring command in the interface view or the undo port command in the ERPS ring view to delete the port from the ERPS ring. Then run the sub-ring command to configure the ERPS ring as a sub-ring.
- (Optional) Run virtual-channel { enable | disable }
The RAPS PDU transmission mode is specified in the sub-ring.
By default, sub-rings use non-virtual-channels (NVCs) to transmit RAPS PDUs. The default transmission mode is recommended. This step takes effect only in a sub-ring.
If the virtual-channel enable command is used to set the VC mode for RAPS PDU transmission in a sub-ring, it is recommended that the control VLAN of the major ring be used to transmit only the RAPS PDUs of the sub-ring. Otherwise, attacks may use bogus RAPS PDUs of the sub-ring to form loops or even fault in the major ring.
- (Optional) Run description text
The description is configured for the ERPS ring.
By default, the description of an ERPS ring is the ERPS ring name, for example, Ring 1.
- Run commit
The configuration is committed.
Configuring the Control VLAN
Context
In an ERPS ring, the control VLAN is used only to forward RAPS PDUs but not service packets, so the security of ERPS is improved. All the devices in an ERPS ring must be configured with the same control VLAN, and different ERPS rings must use different control VLANs.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
The ERPS ring view is displayed.
- Run control-vlan vlan-id
The control VLAN of the ERPS ring is configured.
The control VLAN specified by vlan-id must be a VLAN that has not been created or used.
If you run the control-vlan command multiple times, only the latest configuration takes effect.
If the ERPS ring contains ports, the control VLAN cannot be changed. To delete the configured control VLAN, run the undo erps ring command in the interface view or the undo port command in the ERPS ring view to delete ports from the ERPS ring, and run the undo control-vlan command to delete the control VLAN.
After a control VLAN is created, the vlan batch vlan-id1 [ to vlan-id2 ] &<1-10> command used to create common VLANs is displayed in the configuration file.
- After a port is added to an ERPS ring configured with a control VLAN, the port is added to the control VLAN.
- If the port is a trunk port, the port trunk allow-pass vlan vlan-id command is displayed in the record of the port that has been added to the ERPS ring in the configuration file.
- If the port is a hybrid port, the port hybrid tagged vlan vlan-id command is displayed in the record of the port that has been added to the ERPS ring in the configuration file.
- Run commit
The configuration is committed.
Configuring an ERP Instance and Activating the Mapping Between the ERP Instance and VLAN
Context
On a Layer 2 device running ERPS, the VLAN in which RAPS PDUs and data packets are transmitted must be mapped to an ERP instance so that ERPS forwards or blocks the packets based on configured rules. If the mapping is not configured, the preceding packets may cause broadcast storms on the ring network. As a result, the network becomes unavailable.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
The ERPS ring view is displayed.
- Run protected-instance { all | { instance-id1 [ to instance-id2 ] &<1-10> } }
An ERP instance is created for the ERPS ring.
By default, no ERP instance is configured in an ERPS ring.
If you run the protected-instance command multiple times in the same ERPS ring, multiple ERP instances are configured.
If the ERPS ring contains ports, the ERP instance cannot be changed. To delete the configured ERP instance, run the undo erps ring command in the interface view or the undo port command in the ERPS ring view to delete ports from the ERPS ring, and run the undo protected instance command to delete the ERP instance.
- Run commit
The configuration is committed.
- Run quit
The system view is displayed.
- Configure the mapping between an ERP instance and VLAN.
Run stp region-configuration
The Multiple Spanning Tree (MST) region view is displayed.
Run instance instance-id vlan { vlan-id [ to vlan-id ] } &<1-10>
The mapping between the ERP instance and VLAN is configured.
By default, all VLANs in an MST region are mapped to instance 0.
instance-id in this command must be the same as instance-id used by the protected-instance command.
A VLAN cannot be mapped to multiple MSTIs. If you map a VLAN that has already been mapped to an MSTI to another MSTI, the original mapping will be deleted.
The vlan-mapping modulo modulo command configures the mapping between MSTIs and VLANs based on the default algorithm. However, the mapping configured using this command cannot always meet the actual demand. Therefore, running this command is not recommended.
To configure the mapping between an ERP instance and a MUX VLAN, you are advised to configure the principal VLAN, subordinate group VLANs, and subordinate separate VLANs of the MUX VLAN in the same ERP instance. Otherwise, loops may occur.
Run commit
The configuration is committed.
Adding a Layer 2 Port to an ERPS Ring and Configuring the Port Role
Context
After ERPS is configured, add Layer 2 ports to an ERPS ring and configure port roles so that ERPS can work properly.
In the ERPS ring view, add a specified port to the ERPS ring and configure the port role.
In the interface view, add the current port to the ERPS ring and configure the port role.
A port can be added to a maximum of two ERPS rings.
An ERPS-enabled port needs to allow packets of control VLANs and data VLANs to pass through, so the link type of the port must be configured as trunk or hybrid.
Flush-FDB packets for updating MAC addresses cannot be separately sent, so do not configure a direct link between two upstream nodes as the RPL.
Before changing the port role, use the shutdown command to disable the port. When the port role is changed, use the undo shutdown command to enable the port. This prevents traffic interruptions.
Prerequisites
The port is not a Layer 3 port. If the port is a Layer 3 port, run the portswitch command to switch the port to the Layer 2 mode.
- Spanning Tree Protocol (STP) or Smart Link is not enabled on the port.
- If the port has STP enabled, run the stp disable command in the interface view to disable STP.
- If the port has Smart Link enabled, run the undo port command in the Smart Link group view to disable Smart Link.
The control-vlan command has been executed to configure a control VLAN and the protected-instance command has been executed to configure an ERP instance.
Procedure
- Run system-view
The system view is displayed.
- Add a Layer 2 port to an ERPS ring and configure the port role in either of the following ways.
- In the ERPS ring view, add a specified port to the ERPS ring and configure the port role.
Run interface interface-type interface-number
The interface view is displayed.
Run stp disable
STP is disabled on the ERPS-enabled port.
Run port link-type trunk
The link type of the ERPS-enabled port is configured as trunk.
Run port trunk allow-pass vlan { { vlan-id1 [ to vlan-id2 ] }&<1-10> | all }
The VLANs allowed by the ERPS-enabled port are specified.
After the control-vlan command is used in the ERPS ring view to configure a control VLAN and the port interface-type interface-number [ rpl { owner | neighbour } ] command is configured, the ports in the ERPS ring allow packets of the control VLAN to pass through. Therefore, you need to specify only the IDs of data VLANs in this step.
Run quit
The system view is displayed.
Run erps ring ring-id
The ERPS ring view is displayed.
Run port interface-type interface-number [ rpl { owner | neighbour } ]
The port is added to the ERPS ring and its role is configured.
- In the interface view, add the current port to the ERPS ring and configure the port role.
Run interface interface-type interface-number
The specified interface view is displayed.
Run stp disable
STP is disabled on the ERPS-enabled port.
Run port link-type trunk
The link type of the ERPS-enabled port is configured as trunk.
Run port trunk allow-pass vlan { { vlan-id1 [ to vlan-id2 ] }&<1-10> | all }
The VLANs allowed by the ERPS-enabled port are specified.
After the control-vlan command is used in the ERPS ring view to configure a control VLAN and the port interface-type interface-number [ rpl { owner | neighbour } ] command is configured, the ports in the ERPS ring allow packets of the control VLAN to pass through. Therefore, you need to specify only the IDs of data VLANs in this step.
Run erps ring ring-id [ rpl { owner | neighbour } ]
The current port is added to the ERPS ring and its role is configured.
- In the ERPS ring view, add a specified port to the ERPS ring and configure the port role.
- Run commit
The configuration is committed.
Configuring the Topology Change Notification Function
Context
If an upper-layer Layer 2 network is not notified of the topology change in an ERPS ring, the MAC address entries remain unchanged on the upper-layer network and therefore user traffic is interrupted. To ensure nonstop traffic transmission, configure the topology change notification function and specify the ERPS rings that will be notified of the topology change.
In addition, if an ERPS ring frequently receives topology change notifications, its nodes will have lower CPU processing capability and repeatedly update Flush-FDB packets, consuming much bandwidth. To resolve this problem, set the topology change protection interval at which topology change notifications are sent to suppress topology change notification transmission, and set the maximum number of topology change notifications that can be processed during the topology change protection interval to prevent frequent MAC address and ARP entry updates.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
The ERPS ring view is displayed.
- Run tc-notify erps ring { ring-id1 [ to ring-id2 ] } &<1-10>
The ERPS ring is configured to notify other ERPS rings of its topology change.
ring-id1 [ to ring-id2 ] specifies the start and end ring IDs of the ERPS rings that will be notified of the topology change. Ensure that the ERPS rings specified by ring-id1 and ring-id2 exist. If the specified rings do not exist, the topology change notification function does not take effect.
After the ERPS rings receive the topology change notification from an ERPS ring, they send Flush-FDB messages on their separate rings to instruct their nodes to update MAC addresses so that user traffic is not interrupted.
- (Optional) Run tc-protection interval interval-value
The topology change protection interval at which topology change notification messages are sent is set.
- (Optional) Run tc-protection threshold threshold-value
The number of times ERPS parses topology change notifications and updates forwarding entries in the topology change protection interval is set.
The topology change protection interval is the one specified by the tc-protection interval command.
- Run commit
The configuration is committed.
(Optional) Configuring ERPS Protection Switching
Context
To ensure that ERPS rings function normally when a node or link fails, configure revertive/non-revertive switching, port blocking mode, and timers.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
The ERPS ring view is displayed.
- Run revertive { enable | disable }
The protection switching mode is specified.
By default, ERPS rings use revertive switching.
- Run quit
Return to the system view.
- Perform either of the following operations to configure
a port blocking mode.
To configure a port blocking mode for a port in the ERPS ring view, perform the following steps:
Run the erps ring ring-id command to enter the ERPS ring view.
Run the port interface-type interface-number protect-switch { force | manual } command to configure a port blocking mode for an ERPS port.
To configure a port blocking mode in the interface view, perform the following steps:
Run the interface interface-type interface-number command to enter the interface view.
Run the erps ring ring-id protect-switch { force | manual } command to configure a port blocking mode for the port.
The ERPS ring specified by ring ring-id must be the one to which the port belongs.
To delete the specified port blocking mode, run the clear command in the ERPS ring view.
- Run quit
Return to the system view.
- Run commit
The configuration is committed.
(Optional) Configuring Timers in an ERPS Ring
Context
After a link or node failure in an ERPS ring recovers, the device starts timers in the ERPS ring to reduce traffic interruptions. This prevents network flapping.
Procedure
- Run system-view
The system view is displayed.
- Run erps ring ring-id
The ERPS ring view is displayed.
- Configure the WTR timer, Guard timer, and Holdoff timer in the ERPS ring according to actual networking.
Run wtr-timer time-value
The WTR timer is set.
By default, the WTR timer is 5 minutes in an ERPS ring.
Run guard-timer time-value
The Guard timer is set.
By default, the Guard timer is 200 centiseconds in an ERPS ring.
Run holdoff-timer time-value
The Holdoff timer is set.
By default, the Holdoff timer is 0 deciseconds in an ERPS ring.
- Run commit
The configuration is committed.
Verifying the ERPS Configuration
Procedure
- Run the display erps [ ring ring-id ] [ verbose ] command to check the device ports added to an ERPS ring and ERPS ring configurations.
- Run the display erps interface interface-type interface-number [ ring ring-id ] command to check physical configurations of the port added to an ERPS ring.
- Creating an ERPS Ring
- Configuring the Control VLAN
- Configuring an ERP Instance and Activating the Mapping Between the ERP Instance and VLAN
- Adding a Layer 2 Port to an ERPS Ring and Configuring the Port Role
- Configuring the Topology Change Notification Function
- (Optional) Configuring ERPS Protection Switching
- (Optional) Configuring Timers in an ERPS Ring
- Verifying the ERPS Configuration