13.13 Configuring M-BGP on the PE Routers

This VPN configuration requires that the PE routers have IBGP sessions between them to exchange the VPN routing information. When configuring BGP on these routers, don't forget to define the ASN. This is done in the [edit routing-options] level of the hierarchy. It is also necessary to configure a local-address . The local-address is only relevant when peering from loopback interfaces; however, this is the normal method of peering when configuring IBGP. Since BGP should peer with the loopback interfaces, the BGP configuration will require the addition of configuration statements at both the [edit routing-options] and [edit protocols bgp] levels of the hierarchy.

 [edit routing-options]  lab@Chicago# set autonomous-system  as number  [edit protocols bgp group internal] lab@Chicago# set local-address  local-address  

Note

The local-address defines the source address for establishing the BGP connection. For IBGP sessions, it is necessary to define the loopback0 IP address as the local-address .

 [edit protocols bgp]  lab@Chicago# set group  group name  type [internalexternal] [edit protocols bgp] lab@Chicago# set group  group name  neighbor  address  [edit protocols bgp] lab@Chicago# set group  group name  family inet-vpn unicast The family inet-vpn statement is required to turn up MBGP advertisements of the correct address family 

Use the following commands to verify the BGP configuration:

 lab@Chicago>  show bgp group MY-PE-IBGP-SESSION  Group Type: Internal    AS: 100         Local AS: 100   Name: MY-PE-IBGP-SESSION   Total peers: 1        Established: 1   192.168.2.1+4827   Route Queue Timer: unset Route Queue: empty 

• show bgp group ” This command lists the BGP information on a per-group basis. It can be very useful in providing BGP information for a specific group or routers instead of all routers.

   l  ab@Chicago> show  bgp summary  Groups: 1 Peers: 1 Down peers: 0 Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending inet.0                12         10          0          0          0          0 inet.2                 0          0          0          0          0          0 Peer               AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State#Active/Received/Damped... 192.168.2.1       100         24          5       0       0         1:21 10/12/0             0/0/0 

• show bgp summary ” This command lists a brief summary of the peering sessions with this router.

   lab@Chicago>  show bgp neighbor  Peer: 192.168.2.1+4827 AS 100   Local: 192.168.5.1+179 AS 100   Type: Internal    State: Established    Flags: <>   Last State: OpenConfirm   Last Event: RecvKeepAlive   Last Error: None   Options: <Preference HoldTime Refresh>   Holdtime: 90 Preference: 170   Number of flaps: 0   Peer ID: 192.168.2.1      Local ID: 192.168.5.1      Active Holdtime: 90   Keepalive Interval: 30   NLRI advertised by peer: inet-unicast   NLRI for this session: inet-unicast   Peer supports Refresh capability (2)   Table inet.0 Bit: 10000     Send state: in sync     Active prefixes: 0     Received prefixes: 2     Suppressed due to damping: 0 Last traffic (seconds): Received 4    Sent 0    Checked 0 Input messages:  Total 42     Updates 40      Refreshes 0     Octets 2501 Output messages: Total 8      Updates 0       Refreshes 0     Octets 178 Output Queue[0]: 0