FAQ-NE5000E为什么BGP路由没有添加到IP路由表详细信息中

发布时间:  2011-10-10 浏览次数:  84 下载次数:  0
问题描述
Q:NE5000E为什么BGP路由没有添加到IP路由表详细信息中?
版本:VRP (R) software, Version 5.70 (NE5000E V300R007C00SPC500)

如下:

针对218.75.221.0/24这个网段,dis ip routing-table 218.X.Y.0 verbose中只有优选的O_ASE路由信息,

而没有dis bgp routing-table 218.X.Y.0的路由信息。

<ZZ-ZXJ-CR-1.MAN.NE5000E>dis ip routing-table 218.X.Y.0 verbose
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Table : Public
Summary Count : 2

Destination: 218.X.Y..0/24
     Protocol: O_ASE           Process ID: 1
   Preference: 150                   Cost: 10
      NextHop: 61.187.95.134    Neighbour: 0.0.0.0
        State: Active Adv             Age: 2d02h37m38s
          Tag: 0                 Priority: low
        Label: NULL               QoSInfo: 0x0
   IndirectID: 0x0             
 RelayNextHop: 0.0.0.0          Interface: GigabitEthernet1/0/4
     TunnelID: 0x0                  Flags:  D

Destination: 218.X.Y.0/24
     Protocol: O_ASE           Process ID: 1
   Preference: 150                   Cost: 10
      NextHop: 61.187.95.234    Neighbour: 0.0.0.0
        State: Active Adv             Age: 2d02h37m32s
          Tag: 0                 Priority: low
        Label: NULL               QoSInfo: 0x0
   IndirectID: 0x0             
 RelayNextHop: 0.0.0.0          Interface: GigabitEthernet1/0/5
     TunnelID: 0x0                  Flags:  D

<NE5000E> dis bgp routing-table 218.X.Y..0

 BGP local router ID : 61.137.1.33
 Local AS number : 64903
 Paths:   2 available, 1 best, 1 select
 BGP routing table entry information of 218.X.Y..0/24:
 Imported route.
 From: 0.0.0.0 (0.0.0.0)
 Route Duration: 2d02h37m43s
 Direct Out-interface: GigabitEthernet1/0/4
 Original nexthop: 61.187.95.134
 Qos information : 0x0
 AS-path Nil, origin incomplete, MED 0, suppressed, pref-val 0, valid, local, best, select, pre 150
 Not advertised to any peer yet

 BGP routing table entry information of 218.X.Y..0/24:
 RR-client route.
 From: 61.187.97.6 (61.187.97.6)
 Route Duration: 00h44m27s 
 Relay IP Nexthop: 61.187.95.134
 Relay IP Out-Interface: GigabitEthernet1/0/4
 Original nexthop: 61.187.97.6
 Qos information : 0x0
 AS-path Nil, origin igp, MED 0, localpref 100, pref-val 0, valid, internal, pre 200, not preferred for route type
 Not advertised to any peer yet

而手册中对“dis ip routing-table A.X.Y.Z verbose”的定义:

显示激活和未激活路由的详细信息。不指定该参数,则只显示激活路由的概要信息。

那么为什么上述路由中为什么BGP产生的路由没写入到IP路由表中呢?



处理过程

根因
N/A
解决方案
A:
原因如下:
根据VRP5对IP路由表的添加原则:只添加各协议自己内部优选后的路由。

这个是正常现象,BGP中优选的是引入路由,也就是说BGP优选的路由是从IP路由表中优选的那条ospf路由,BGP从IP路由表中引入的路由不需要再添加到ip路由表中(添加的话没意义,ip路由表中本身就有这条路由)。

我们可以注意到:

<NE5000E> dis bgp routing-table 218.X.Y..0

 BGP local router ID : 61.137.1.33
 Local AS number : 64903
 Paths:   2 available, 1 best, 1 select
 BGP routing table entry information of 218.X.Y..0/24:
 Imported route.===BGP中优选的是引入路由,也就是说优选的是从IP路由表中优选的那条ospf路由
 From: 0.0.0.0 (0.0.0.0)
 Route Duration: 2d02h37m43s
 Direct Out-interface: GigabitEthernet1/0/4
 Original nexthop: 61.187.95.134
 Qos information : 0x0
 AS-path Nil, origin incomplete, MED 0, suppressed, pref-val 0, valid, local, best, select, pre 150
 Not advertised to any peer yet

 BGP routing table entry information of 218.X.Y..0/24:
 RR-client route.
 From: 61.187.97.6 (61.187.97.6)
 Route Duration: 00h44m27s 
 Relay IP Nexthop: 61.187.95.134
 Relay IP Out-Interface: GigabitEthernet1/0/4
 Original nexthop: 61.187.97.6
 Qos information : 0x0
 AS-path Nil, origin igp, MED 0, localpref 100, pref-val 0, valid, internal, pre 200, not preferred for route type
 Not advertised to any peer yet


建议与总结

END