No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

CLI-based Configuration Guide - IP Unicast Routing

AR100, AR120, AR150, AR160, AR200, AR1200, AR2200, AR3200, and AR3600 V200R010

This document describes the concepts and configuration procedures of IP Service features on the device, and provides the configuration examples.
Rate and give feedback :
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 Attributes for LSPs

Configuring Attributes for LSPs

Context

LSPs are used to exchange link state information. You can configure attributes for LSPs to control the length and maximum lifetime of LSPs. To accelerate network convergence, you can enable LSP fast flooding or reduce the minimum interval for sending LSPs and the interval for updating LSPs to speed up LSP flooding. However, CPU resources will be consumed too much if the network topology changes frequently. In this situation, configure the intelligent timer for generating LSPs. This timer can fast respond to emergencies, speed up network convergence, and improve CPU resource efficiency because its interval becomes longer when the network changes frequently.

Configured Parameters Function Usage Scenario
Set the maximum length for LSPs Set the size for LSPs to be generated and LSPs to be received. When the volume of link status information increases, the length of LSPs to be generated can be increased to carry more information in each LSP.
Set the maximum lifetime for LSPs Set the maximum lifetime for LSPs to ensure the validity of an LSP before its updated LSP is received. When a router generates the system LSP, it fills in the maximum lifetime for this LSP. After this LSP is received by other routers, the lifetime of the LSP is reduced gradually. If the router does not receive any more update LSPs and the lifetime of the LSP is reduced to 0, the LSP will be deleted from the LSDB 60s later if no more updated LSPs are received.
Set the refresh interval for LSPs Set the refresh interval for LSPs to synchronize LSDBs. On an IS-IS network, LSDB synchronization is implemented through LSP flooding. During LSP flooding, a router sends an LSP to its neighbors and then the neighbors send the received LSP to their respective neighbors except the router that first sends the LSP. In this manner, the LSP is flooded among the routers of the same level. LSP flooding allows each router of the same level to have the same LSP information and synchronize its LSDB with each other.
Set the minimum interval at which LSPs are sent Set the interval for sending an LSP during LSP update. Reducing the minimum interval for sending LSPs speeds up LSP flooding.
Configure the intelligent timer used to generate LSPs Control the interval for generating LSPs intelligently to speed up route convergence and reduce system load. On an IS-IS network, if the local routing information changes, a router needs to generate a new LSP to notify this change. If the local routing information changes frequently, a large number of new LSPs are generated, which occupies a lot of system resources and decreases system performance. To speed up network convergence and prevent system performance from being affected, configure an intelligent timer for generating LSPs. This timer can adjust the delay in generating LSPs based on the routing information change frequency.
Enable LSP fast flooding Control the number of LSPs flooded each time on an interface to speed up IS-IS network convergence. When an IS-IS router receives new LSPs from other routers, it router updates the LSPs in the local LSDB and periodically floods out the updated LSPs according to a timer. LSP fast flooding updates the preceding method. When a device configured with LSP fast flooding receives one or more new LSPs. it floods out the LSPs with a number smaller than the specified number before calculating routes. This speeds up LSDB synchronization.
Set an interval at which LSPs are retransmitted over a P2P link Control the interval for retransmitting LSPs to ensure LSDB synchronization on a P2P network. On a point-to-point network, devices at both ends of a link synchronize LSDBs with each other by flooding LSPs. The device at one end of the link sends an LSP. If the device at the other end receives this LSP, it replies with a PSNP. If the device that has sent an LSP does not receive a PSNP from the other end in a period of time, the device will retransmit the LSP.

Procedure

  • Set the maximum length for LSPs.
    1. Run system-view

      The system view is displayed.

    2. Run isis [ process-id ]

      The IS-IS view is displayed.

    3. Set the maximum length for LSPs.

      • Run lsp-length originate max-size

        The maximum length is set for each generated LSP.

      • Run lsp-length receive max-size

        The maximum length is set for each received LSP.

      By default, the IS-IS system generates and receives 1497-byte LSPs.

      NOTE:

      Ensure that the value of max-size for LSPs to be generated must be smaller than or equal to the value of max-size for LSPs to be received.

      The value of max-size set through the lsp-length command must meet the following requirements; otherwise, the MTU status on the interface is considered Down.
      • The MTU of an Ethernet interface must be greater than or equal to the sum of the value of max-size and 3.

      • The MTU of a P2P interface must be greater than or equal to the value of max-size.

  • Set the maximum lifetime for LSPs.
    1. Run system-view

      The system view is displayed.

    2. Run isis [ process-id ]

      The IS-IS view is displayed.

    3. Run timer lsp-max-age age-time

      The maximum lifetime is set for LSPs.

      By default, the maximum lifetime of LSPs is 1200 seconds.

  • Set the refresh interval for LSPs.
    1. Run system-view

      The system view is displayed.

    2. Run isis [ process-id ]

      The IS-IS view is displayed.

    3. Run timer lsp-refresh refresh-time

      A refresh interval is set for LSPs.

      By default, the LSP refresh interval is 900s.

      NOTE:

      Ensure that the LSP refresh interval is more than 300s shorter than the maximum LSP lifetime. This allows new LSPs to reach all devices in an area before existing LSPs expire.

      The larger a network, the greater the deviation between the LSP refresh interval and the maximum LSP lifetime.

  • Set the minimum interval at which LSPs are sent.
    1. Run system-view

      The system view is displayed.

    2. Run interface interface-type interface-number

      The interface view is displayed.

    3. Run isis timer lsp-throttle throttle-interval [ count count ]

      The minimum interval for sending LSPs on an IS-IS interface and the maximum number of LSPs sent within the interval are set.

      By default, the minimum interval for sending LSPs is 50 ms, and the maximum number of LSPs sent each time is 10.

  • Configure the intelligent timer used to generate LSPs.
    1. Run system-view

      The system view is displayed.

    2. Run isis [ process-id ]

      The IS-IS view is displayed.

    3. Run timer lsp-generation max-interval [ init-interval [ incr-interval ] ] [ level-1 | level-2 ]

      The intelligent timer used to generate LSPs is set.

      If no level is configured, both Level-1 and Level-2 are configured.

      The delay for generating the same LSPs (or LSP fragments) for the first time is init-interval. The delay for generating the same LSPs (or LSP fragments) for the second time is incr-interval. When the routes change each time, the delay for generating the same LSPs (or LSP fragments) is twice as the previous value until the delay is up to max-interval. After the delay reaches max-interval for three times or reset the IS-IS process, the interval is reduced to init-interval.

      When incr-interval is not used and generating the same LSPs (or LSP fragments) for the first time, init-interval is used as the initial delay. Then, the delay for generating the same LSPs (or LSP fragments) is max-interval. After the delay reaches max-interval for three times or the IS-IS process is reset, the interval is reduced to init-interval.

      When only max-interval is used, the intelligent timer changes into a normal one-short timer.

  • Enable LSP fast flooding.
    1. Run system-view

      The system view is displayed.

    2. Run isis [ process-id ]

      The IS-IS view is displayed.

    3. Run flash-flood [ lsp-count | max-timer-interval interval | [ level-1 | level-2 ] ]*

      The LSP fast flooding is enabled.

      The lsp-count parameter specifies the number of LSPs flooded each time, which is applicable to all interfaces. If the number of LSPs to be sent is greater than the value of lsp-count, lsp-count takes effect. If the number of LSPs to be sent is smaller than the value of lsp-count, LSPs of the actual number are sent. If a timer is configured and the configured timer does not expire before the route calculation, the LSPs are flooded immediately when being received; otherwise, the LSPs are sent when the timer expires.

      When LSP fast flooding is enabled, Level-1 LSPs and Level-2 LSPs are fast flooded by default if no level is specified.

  • Set an interval at which LSPs are retransmitted over a P2P link.
    1. Run system-view

      The system view is displayed.

    2. Run interface interface-type interface-number

      The interface view is displayed.

    3. (Optional) Run isis circuit-type p2p [ strict-snpa-check ]

      A broadcast interface is simulated as a P2P interface.

      NOTE:

      If the interface type is P2P, this step is not required.

    4. Run isis timer lsp-retransmit retransmit-interval

      The interval at which LSPs are retransmitted over a P2P link is set.

      By default, the interval for retransmitting LSPs over a P2P link is 5 seconds.

Translation
Download
Updated: 2019-05-20

Document ID: EDOC1100034072

Views: 109639

Downloads: 155

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next