基于VRF的BGP建联

本文解决核心问题是单一CE节点到PE节点指定VRF的BGP建邻居。

  整体网络拓扑上图所示，PE汇聚路由已与边缘客户路由建邻，指派10.10.10.0/24网段。重点：其中PE端上与CE端互联的端口必须已指定到创建好的vrf或netns上，该工作需要LinuxShell中执行iproute2命令。

1.PE

汇聚路由BGP设置入下图所示

router bgp 100
 bgp router-id 10.10.20.2
!
router bgp 100 vrf vrf1
 bgp router-id 10.10.10.1
 neighbor 10.10.10.2 remote-as 50
 !
 address-family ipv4 unicast
  rd vpn export 100:10
  rt vpn both 100:10
 exit-address-family
!

2.CE

边缘路由BGP设置入下图所示

router bgp 50
 bgp router-id 10.10.10.2
 network 192.168.1.0/24
 neighbor 10.10.10.1 remote-as 100
!

3.查询BGP联通

#通过如下命令，确认BGP建立连接状态;其中00:19:34后面的数字1,代表接收的路由条目；
$show ip bgp vrf vrf1 summary
IPv4 Unicast Summary:
BGP router identifier 10.10.10.1, local AS number 100 vrf-id 1
BGP table version 1
RIB entries 1, using 184 bytes of memory
Peers 1, using 20 KiB of memory

Neighbor        V         AS MsgRcvd MsgSent   TblVer  InQ OutQ  Up/Down State/PfxRcd
10.10.10.2      4         50      24      23        0    0    0 00:19:34            1
Total number of neighbors 1

#通过如下命令，确定转发到vrf1中的路由
$show ip bgp vrf vrf1
BGP table version is 1, local router ID is 10.10.10.1, vrf id 1
Default local pref 100, local AS 100
Status codes:  s suppressed, d damped, h history, * valid, > best, = multipath,
               i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes:  i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 192.168.1.0/24   10.10.10.2               0             0 50 i

Displayed  1 routes and 1 total paths