ME60 对应的VPN实例g-pc下面学习不了某条路由

发布时间:  2017-03-31 浏览次数:  380 下载次数:  0
问题描述
简略图如下:

ME60------------NE40  

两台设备直连走 option B 建立EBGP对等体,NE40学习10.1.80.0路由,并已发布给对等休ME60,但在ME60VPN实例g-pc下没有这条路由,NE40ME60两个VPN实例都有对应RT值。

处理过程
 

1、查看NE40信息,VPN实例配置,如下:

ip vpn-instance g-vm

ipv4-family

  route-distinguisher 10.79.251.3:21

  vpn-target 1:6 100:0 300:0 export-extcommunity

  vpn-target 1:1 1:5 1:6 64003:1 64003:3 64003:4 import-extcommunity

 

查看实例路由,如下:

<pek14arthw13>dis ip routing-table vpn-instance g-vm 10.1.81.0

Route Flags: R - relay, D - download to fib

------------------------------------------------------------------------------

Routing Table : g-vm

Summary Count : 1

Destination/Mask    Proto   Pre  Cost      Flags NextHop         Interface

 

      10.1.80.0/20  IBGP    255  0          RD   172.23.5.1      GigabitEthernet8/1/0            //NE40有学习到这条路由

 

<pek14arthw13>dis bgp vpnv4 all routing-table 10.1.81.0

 

BGP local router ID : 10.79.251.3

Local AS number : 64539

 

Total routes of Route Distinguisher(10.79.100.3:21): 2

BGP routing table entry information of 10.1.80.0/20:

Label information (Received/Applied): 101018/33945

From: 172.23.5.1 (172.23.5.1)

Route Duration: 149d11h04m45s

 Relay IP Nexthop: 172.23.5.129

Relay IP Out-Interface: GigabitEthernet8/1/0

Relay Tunnel Out-Interface: GigabitEthernet8/1/0

Relay token: 0x4000015

Original nexthop: 172.23.5.1

Qos information : 0x0

Ext-Community:RT <64003 : 3>

AS-path 65108 65050 65002, origin incomplete, localpref 100, pref-val 0, valid, internal, best, select, pre 255

Advertised to such 4 peers:

    172.23.5.22

    172.23.5.34                //路由已经发布给ME60NE40GE3/0/0接口IP172.23.5.34

    172.23.5.46

    172.23.5.62

BGP routing table entry information of 10.1.80.0/20:

Label information (Received/Applied): 43088/NULL

 

2、查看ME60信息,VPN实例配置,如下:

ip vpn-instance g-pc

ipv4-family

  route-distinguisher 10.79.251.34:23

  vpn-target 1:5 100:0 300:0 export-extcommunity

  vpn-target 1:1 1:5 1:6 64003:1 64003:4 import-extcommunity

 

<pek14amghw14>dis ip routing-table vpn-instance g-pc 10.1.81.0                //g-pc下面无此路由

<pek14amghw14>dis bgp vpnv4 all routing-table  10.1.81.0                     //VPNV4下面有这条路由并且最优

 

BGP local router ID : 10.79.251.34

Local AS number : 65119

 

Total routes of Route Distinguisher(10.79.100.3:21): 2

BGP routing table entry information of 10.1.80.0/20:

Label information (Received/Applied): 33945/36130

From: 172.23.5.33 (10.79.251.3)

Route Duration: 149d10h59m28s

 Relay Tunnel Out-Interface: GigabitEthernet3/0/0

Relay token: 0x46004000

Original nexthop: 172.23.5.33

Qos information : 0x0

Ext-Community:RT <64003 : 3>              //RT值是640033

AS-path 64539 65108 65050 65002, origin incomplete, pref-val 0, valid, external, best, select, pre 255

Advertised to such 1 peers:

    10.79.251.35

BGP routing table entry information of 10.1.80.0/20:

Label information (Received/Applied): 8535/NULL

From: 10.79.251.35 (10.79.251.35)

Route Duration: 149d10h59m25s

 Relay IP Nexthop: 172.23.5.38

Relay IP Out-Interface: Eth-Trunk0

Relay Tunnel Out-Interface: Eth-Trunk0

Relay token: 0x57

Original nexthop: 10.79.251.35

Qos information : 0x0

Ext-Community:RT <64003 : 3>

AS-path 64539 65108 65050 65002, origin incomplete, localpref 100, pref-val 0, valid, internal, pre 255, IGP cost 1, not preferred for peer type

Not advertised to any peer yet      

3、路由都能学习过来,自然BGP邻居也是正常建立的。如下:

   综上所述,ME60VPN实例已经学习到此路由,只是没有加入到对应的实例中,影响路由加表的因素,通常有RT值不匹配,或设置了路由过滤策略,根据这主要的个方面去再确认下,在第3步中查看ME60上的路由信息时,此路由携带的RT值是640033而根据NE40ME60上的VPN实例的RT值看,在NE40上面有匹配的RT值,所以路由在加入VPN实例中,ME60上则无此RT值,导致路由不能加入VPN实例中。

根因
从而问题根因确认,是由于ME60上没有匹配的RT值导致路由不能正常加入VPN实例。
解决方案
ME60对应VPN实例中添加入策略RT值是640033,或者在发布此路由的设备上添加ME60对应的RT值。

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