使用LDP建立LSP示例

操作步骤

1. 配置LDP LSP

   在完成配置本地LDP会话示例后，各LSR已根据默认的LDP LSP触发策略，即32位地址的主机IP路由触发LDP建立LSP。

   # 在各LSR上执行display mpls ldp lsp命令，可以看到所有主机路由都触发建立了LDP LSP。

   以LSRA的显示为例：

   [~LSRA] display mpls ldp lsp

    
    LDP LSP Information
    -------------------------------------------------------------------------------
    DestAddress/Mask   In/OutLabel    UpstreamPeer    NextHop          OutInterface
    -------------------------------------------------------------------------------
    1.1.1.9/32         3/NULL         2.2.2.9         127.0.0.1        Loop1
   *1.1.1.9/32         Liberal/3                      DS/2.2.2.9
    2.2.2.9/32         NULL/3         -               10.1.1.2         GE0/1/0
    2.2.2.9/32         1024/3         2.2.2.9         10.1.1.2         GE0/1/0
    3.3.3.9/32         NULL/1025      -               10.1.1.2         GE0/1/0
    3.3.3.9/32         1025/1025      3.3.3.9         10.1.1.2         GE0/1/0     
    ------------------------------------------------------------------------------
    TOTAL: 5 Normal LSP(s) Found.
    TOTAL: 1 Liberal LSP(s) Found.
    TOTAL: 0 Frr LSP(s) Found.
   An asterisk (*) before an LSP means the LSP is not established
    An asterisk (*) before a Label means the USCB or DSCB is stale
    An asterisk (*) before an UpstreamPeer means the session is stale
    An asterisk (*) before a DS means the session is stale
    An asterisk (*) before a NextHop means the LSP is FRR LSP
   

   推荐使用缺省的触发策略，即32位地址的主机IP路由触发LDP建立LSP。也可以根据实际需要，执行以下步骤修改LDP LSP的触发策略。

2. 修改LDP LSP的触发策略

   在各LSR上将LDP LSP的触发策略修改为all，使路由表中的所有静态路由和IGP表项都允许触发建立LDP LSP。

   # 配置LSRA。

   [~LSRA] mpls

   [~LSRA-mpls] lsp-trigger all

   [*LSRA-mpls] commit

   [~LSRA-mpls] quit

   # 配置LSRB。

   [~LSRB] mpls

   [~LSRB-mpls] lsp-trigger all

   [*LSRB-mpls] commit

   [~LSRB-mpls] quit

   # 配置LSRC。

   [~LSRC] mpls

   [~LSRC-mpls] lsp-trigger all

   [*LSRC-mpls] commit

   [~LSRC-mpls] quit

3. 检查配置结果

   # 配置完成后，在各节点上执行display mpls ldp lsp命令，可以看到LDP LSP的建立情况。以LSRA的显示为例。

   [~LSRA] display mpls ldp lsp

   LDP LSP Information
    -------------------------------------------------------------------------------
    DestAddress/Mask   In/OutLabel   UpstreamPeer    NextHop     OutInterface
    -------------------------------------------------------------------------------
    1.1.1.9/32         3/NULL        2.2.2.9         127.0.0.1   Loop1    
   *1.1.1.9/32         Liberal/3                     DS/2.2.2.9
    2.2.2.9/32         NULL/3        -               10.1.1.2    GE0/1/0    
    2.2.2.9/32         1024/3        2.2.2.9         10.1.1.2    GE0/1/0    
    3.3.3.9/32         NULL/1025     -               10.1.1.2    GE0/1/0    
    3.3.3.9/32         1025/1025     2.2.2.9         10.1.1.2    GE0/1/0    
    10.1.1.0/30        3/NULL        2.2.2.9         10.1.1.1    GE0/1/0    
   *10.1.1.0/30        Liberal/3                     DS/2.2.2.9
    10.2.1.0/30        NULL/3        -               10.1.1.2    GE0/1/0    
    10.2.1.0/30        1026/3        2.2.2.9         10.1.1.2    GE0/1/0    
    -------------------------------------------------------------------------------
    TOTAL: 8 Normal LSP(s) Found.
    TOTAL: 2 Liberal LSP(s) Found.
    TOTAL: 0 Frr LSP(s) Found.
   An asterisk (*) before an LSP means the LSP is not established
    An asterisk (*) before a Label means the USCB or DSCB is stale
    An asterisk (*) before an UpstreamPeer means the session is stale
    An asterisk (*) before a DS means the session is stale
    An asterisk (*) before a NextHop means the LSP is FRR LSP