IS-IS快速收敛示例

组网需求

  1. 两台路由器通过交换机相连,并通过IS-IS协议实现互联互通
  2. 要求提高两台路由器的收敛速度

实验拓扑

配置思路

  1. 路由器基础配置以及IP地址
  2. 配置IS-IS协议,实现互联互通
  3. Router A 和Router B上配置BFD会话,提高设备对链路故障的感知
  4. Router A和Router B上配置收敛时间参数,实现IS-IS网络的快速收敛

配置命令

  1. 路由器基础配置以及IP地址

    • Router A配置

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      sys
      sys Router A
      int g0/0/0
      ip add 100.1.1.1 30
  • Router B配置

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    sys
    sys Router B
    int g0/0/0
    ip add 100.1.1.2 30
  1. 配置IS-IS协议以及接口使能IS-IS协议

    • Router A配置

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      sys
      isis 1
      is-level level-2
      network-entity 1000.0100.1001.00
  • Router B配置

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    sys
    isis 1
    is-level level-2
    network-entity 1000.0100.1002.00
  1. 配置IS-IS协议与静态BFD会话

    • Router A配置

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      sys

      #配置全局BFD
      bfd
      q

      #配置静态BFD并绑定邻居
      bfd A-To-B bind peer-ip 100.1.1.2 interface g0/0/0
      #配置本地和远程识别器
      discriminator local 1
      discriminator remote 2
      commit
      quit
      #接口使能IS-IS与BFD绑定
      int g0/0/0
      isis bfd static
      quit
  • Router B配置

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      sys

    #配置全局BFD
    bfd
    q

    #配置静态BFD并绑定IS-IS邻居
    bfd B-To-A bind peer-ip 100.1.1.1 interface g0/0/0
    #配置本地和远程是识别器
    discrimination local 2
    discrimination remote 1
    commit
    quit

    #接口使能IS-IS与BFD绑定
    int g0/0/0
    isis bfd static
    quit
  1. 配置收敛时间参数

    • Router A配置

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      sys
      isis 1

      #配置收敛时间 使能LSP快速收敛
      flash-flood #Configure the flash(快速发送) flood(泛洪) feature(特性)

      # The timer for SPF calculations 设置SPF计算的时间间隔
      timer spf
      1 # Maximum interval between ISPFs 设置ISPF之间的最大时间间隔,默认为5秒,单位为秒
      20 #Initial interval betweeen ISPFs 设置ISPF之间的初始时间间隔,默认为50毫秒,单位为毫秒
      120 #Incremental interval between ISPFs 设置ISPF之间的增加时间间隔,默认为200毫秒,单位是毫秒

      # Set the intelligent(智能的) timer for LSP generation(产生) 设置产生LSP的延迟时间,缺省值为2秒
      timer lsp-generation
      1 # Set the intelligent(智能的) timer maximum(最大的) interval(间隔),单位为秒
      1 # Set the intelligent(智能的) timer initial(最初的) interval(间隔),单位为毫秒
      120 # Set the intelligent(智能的) timer increment(增加) interval(间隔),单位为毫秒
  • Router B配置

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    sys
    isis 1

    #使能LSP快速收敛
    flash-flood

    # The timer for SPF calculations 设置SPF计算时间间隔
    timer spf
    1 # Maximum interval between ISPFs 设置ISPF之间的最大时间间隔,默认为5秒,单位为秒
    1 # Initial interval between ISPFs 设置ISPF之间的最初时间间隔,默认为50毫秒,单位为毫秒
    120 # Incremental interval between ISPFs 设置ISPF之间的增加时间间隔,默认为200毫秒,单位为好

    # Set the intelligent timer for LSP generation 设置LSP产生的时间间隔,缺省值为2秒
    timer lsp-generation
    1 # Set the intelligent timer maximum interval,设置智能时间的最大时间间隔,单位为秒
    1 # Set the intelligent timer initial interval,设置智能时间的最初时间间隔,单位为毫秒
    120 # Set the intelligent timer increment interval,设置智能时间的增长时间间隔,单位为毫秒

查看命令

  1. 将Router B端口down掉

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    [Router B]int g0/0/0
    [Router B-GigabitEthernet0/0/0]shutdown

    Feb 18 2022 09:40:25-08:00 Router B %%01IFPDT/4/IF_STATE(l)[0]:Interface Gigabit
    Ethernet0/0/0 has turned into DOWN state.
    [Router B-GigabitEthernet0/0/0]
    Feb 18 2022 09:40:25-08:00 Router B %%01BFD/4/STACHG_TODWN(l)[1]:BFD session cha
    nged to Down. (SlotNumber=0, Discriminator=33554432, Diagnostic=DetectDown, Appl
    ications=None, ProcessPST=False, BindInterfaceName=GigabitEthernet0/0/0, Interfa
    cePhysicalState=Up, InterfaceProtocolState=Up)
    [Router B-GigabitEthernet0/0/0]
    Feb 18 2022 09:40:25-08:00 Router B %%01ISIS/4/PEER_DOWN_BFDDOWN(l)[2]:ISIS 256
    neighbor 1000.0100.1001 was Down on interface GE0/0/0 because the BFD node was d
    own. The Hello packet was received at 09:32:38 last time; the maximum interval f
    or sending Hello packets was 1276641280; the local router sent 3423272960 Hello
    packets and received 100663296 packets; the type of the Hello packet was Lan Lev
    el-2.
    [Router B-GigabitEthernet0/0/0]
    Feb 18 2022 09:40:25-08:00 Router B %%01ISIS/4/ADJ_CHANGE_LEVEL(l)[3]:The neighb
    or of ISIS was changed. (IsisProcessId=256, Neighbor=1000.0100.1001, InterfaceNa
    me=GE0/0/0, CurrentState=up, ChangeType=L2_BFD_DOWN, Level=Level-2)
    [Router B-GigabitEthernet0/0/0]
    Feb 18 2022 09:40:25-08:00 Router B %%01ISIS/4/ADJ_CHANGE_LEVEL(l)[4]:The neighb
    or of ISIS was changed. (IsisProcessId=256, Neighbor=1000.0100.1001, InterfaceNa
    me=GE0/0/0, CurrentState=down, ChangeType=L2_HOLDTIMER_EXPIRED, Level=Level-2)
    [Router B-GigabitEthernet0/0/0]
    Feb 18 2022 09:40:25-08:00 Router B %%01IFNET/4/LINK_STATE(l)[5]:The line protoc
    ol IP on the interface GigabitEthernet0/0/0 has entered the DOWN state.
  1. Router A的邻居消失
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