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

Configuration Guide - IP Routing 01

NE05E and NE08E V300R003C10SPC500

This is NE05E and NE08E V300R003C10SPC500 Configuration Guide - IP Routing
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).
Improving OSPFv3 Network Stability

Improving OSPFv3 Network Stability

A stable OSPFv3 network features less route flapping, normal router performance, and high network performance.

Usage Scenario

By setting timers, you can reduce the number of unnecessary packets on networks and the load on the device, and improve network performance.

By adjusting the SPF calculation interval, you can mitigate resource consumption due to frequent network changes.

Pre-configuration Tasks

Before improving the security of an OSPFv3 network, complete the following tasks:

  • Configure a link layer protocol.

  • Configure IPv6 addresses for interfaces to ensure that neighboring nodes are reachable at the network layer.

  • Configure basic OSPF3 functions.

Configuration Procedures

Perform one or more of the following configurations as required.

Setting the Priority of OSPFv3

If multiple dynamic routing protocols run on a device, the device needs to select optimal routes from the routes of these protocols. In this case, you can set a priority for each routing protocol. In this manner, when different protocols discover the routes to the same destination, the route discovered by the protocol with the highest priority is selected.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run ospfv3 [ process-id ]

    The OSPFv3 view is displayed.

  3. Run preference [ ase ] { preference | route-policy route-policy-name | route-filter route-filter-name } *

    The priority of OSPF is set.

    • The parameter ase sets the priority for AS-external routes.
    • The parameter preference specifies the priority for OSPF routes. The smaller the value, the higher the priority.
    • route-policy route-policy-name specifies the name of a route-policy used to filter routes.
    • route-filter route-filter-name specifies the name of a route-filter used to filter routes.

  4. Run commit

    The configuration is committed.

Setting the Delay in Transmitting LSAs on the Interface

It takes time to transmit OSPFv3 packets on a link. Therefore, a certain delay is added to the aging time of an LSA before the LSA is sent. This configuration is especially necessary on low-speed links.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run interface interface-type interface-number

    The OSPFv3 interface view is displayed.

  3. Run ospfv3 trans-delay interval [ instance instance-id ]

    The delay in transmitting LSAs is set on the interface.

    By default, the delay in transmitting LSAs is 1s.

  4. Run commit

    The configuration is committed.

Setting the Interval at Which LSAs Are Retransmitted Between Adjacent Routers

After a router sends an LSA to its neighbor, the router expects to receive an LSAck packet from the neighbor. If the router does not receive an LSAck packet within the LSA retransmission interval, it retransmits the LSA to the neighbor.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run interface interface-type interface-number

    The OSPFv3 interface view is displayed.

  3. Run ospfv3 timer retransmit interval [ instance instance-id ]

    The interval at which LSAs are retransmitted between adjacent NEs is set.

    By default, the interval is 5 seconds.

    NOTE:

    Set a proper interval to avoid unnecessary LSA retransmission, and set a value greater than the round trip time of a packet transmitted between two NEs is recommended.

  4. Run commit

    The configuration is committed.

Configuring a Route Calculation Delay to Suppress Frequent LSA Flapping

Context

Frequent OSPFv3 LSA flapping may lead to route flapping, adversely affecting services. To address this problem, run the maxage-lsa route-calculate-delay command to configure the device to delay route calculation when it receives a MaxAge Router LSA, which suppresses the frequent OSPFv3 LSA flapping that may occur.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run ospfv3 [ process-id ]

    The OSPFv3 view is displayed.

  3. Run maxage-lsa route-calculate-delay delay-interval

    A route calculation delay is configured and will be triggered when the device receives a MaxAge Router LSA.

    By default, the delay is 10s.

  4. Run commit

    The configuration is committed.

Configuring the SPF Timer

By setting the interval for Shortest Path First (SPF) calculation, you can reduce resource consumption caused by frequent network changes.

Context

Whenever the Link-state Database (LSDB) of OSPFv3 changes, the shortest path should be recalculated. Calculating the shortest path each time the LSDB changes consumes enormous resources and lowers the efficiency of a NE.

Adjusting the SPF delay and hold interval can suppress frequent network changes to avoid resource consumption.

Procedure

  • Configure an SPF normal timer.
    1. Run system-view

      The system view is displayed.

    2. Run ospfv3 [ process-id ]

      The OSPFv3 view is displayed.

    3. Run spf timers delay-interval hold-interval

      An SPF normal timer is configured.

    4. Run commit

      The configuration is committed.

  • Configure an SPF intelligent timer.
    1. Run system-view

      The system view is displayed.

    2. Run ospfv3 [ process-id ]

      The OSPFv3 view is displayed.

    3. Run spf-schedule-interval { delay-interval hold-interval | intelligent-timer max-interval start-interval hold-interval-1 }

      An SPF intelligent timer is configured.

      In a networking environment, in which the convergence time of routes is required to be shorter, you can set millisecond as the unit of interval to increase the frequency of calculating routes. Route convergence therefore speeds up. In other networking environments, the default value is recommended.

      The interval for the SPF calculation is as follows:
      1. The initial interval for the SPF calculation is specified in start-interval.
      2. The interval for the SPF calculation for the nth (n≥2) time is equal to hold-interval × 2(n-2).
      3. When the interval specified in hold-interval × 2(n-2) reaches the maximum interval specified in max-interval, OSPFv3 performs the SPF calculation at the maximum interval until no SPF calculation is performed within max-interval. After the maximum interval elapses, the calculation mechanism goes back to step 1.
      4. If no flapping occurs within the interval of max-interval that starts upon the end of the previous SPF calculation, the intelligent timer exits.

      5. If no flapping occurs in the previous interval and flapping occurs in the current interval, SPF calculation is delayed for a period of the start-interval. After the SPF calculation is complete, the current interval is used for the next SPF calculation.

      NOTE:
      An SPF normal timer and an SPF intelligent timer are mutually exclusive.

    4. Run commit

      The configuration is committed.

Configuring a Stub Router

When the device is overloaded and cannot forward any other packets, you can configure it as a stub NE. After the NE is configured as a stub NE, other OSPFv3 devices do not use this device to forward data, but they can have a route to this stub NE.

Context

A stub NE controls traffic and instruct other OSPFv3 devices not to use it to forward data. Other OSPFv3 devices can have a route to the stub NE.

The link cost in the Router LSAs generated by the stub NE is set to the maximum value (65535).

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run ospfv3 [ process-id ]

    The OSPFv3 view is displayed.

  3. Run stub-router [ on-startup [ interval ] ]

    A stub NE is configured.

    The parameter on-startup [ interval ] specifies the interval during which the NE remains a stub NE. By default, the interval is 500 seconds.

    NOTE:

    The stub NE configured through this command has nothing to do with the NEs in a stub area.

  4. Run commit

    The configuration is committed.

Verifying the Configuration of OSPFv3 Network Stability

After improving the OSPFv3 network stability, verify brief information about OSPFv3 and the IP routing table.

Procedure

  • Run the display ospfv3 [ process-id ] interface [ no-peer | area area-id ] [ interface-type interface-number ] command in any view to view information about an OSPFv3 interface.
  • Run the display ospfv3 [ process-id ] routing command in any view to view information about an OSPFv3 routing table.
  • Run the display ospfv3 [ process-id ] statistics maxage-lsa command to check information about MaxAge Router-LSAs.

Example

Run the display ospfv3 interface command to view the values of OSPFv3 timers.

<HUAWEI> display ospfv3 interface
GE0/1/0 is up, line protocol is up
  Interface ID 0x102
  IPv6 Prefixes
    FE80::2E0:FFF:FE4E:F101 (Link-Local Address)
    2000::1/64
  OSPFv3 Process (1), Area 0.0.0.1, Instance ID 0
    Router ID 1.1.1.1, Network Type BROADCAST, Cost: 1
    Transmit Delay is 1 sec, State Full, Priority 1
    No designated router on this link
    No backup designated router on this link
    Timer interval configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:02
    Neighbor Count is 0, Adjacent neighbor count is 0

Run the display ospfv3 routing command to view the destination addresses, link costs, and next hops of OSPFv3 routes.

<HUAWEI> display ospfv3 routing
 Codes : E2 - Type 2 External, E1 - Type 1 External, IA - Inter-Area
 OSPFv3 Process (1)
   Destination                                Metric
     Nexthop
   2000:1::/64                                 3124
     via FE80::1441:0:E213:1, GigabitEthernet0/1/0

Run the display ospfv3 [ process-id ] statistics maxage-lsa command to view information about MaxAge Router-LSAs.

<HUAWEI> display ospfv3 statistics maxage-lsa
          OSPFV3 Process 1 with Router ID 1.1.1.1 
                  Statistics of Router-LSAs 
          --------------------------------------------------- 
                          Area: 0.0.0.0 
Origin Router                MaxAge count     Last MaxAge time 
1.1.1.1                                 0  0000-00-00 00:00:00 
Translation
Download
Updated: 2019-01-14

Document ID: EDOC1100058916

Views: 38050

Downloads: 57

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