Configure an IBGP Session between PE Routers

You must configure an internal Border Gateway Protocol (IBGP) session between the PE routers to allow the PE routers to exchange information about routes originating and terminating in the VPN. The PE routers rely on this information to determine which labels to use for traffic destined for remote sites.

Configure an IBGP session for the VPN at the [edit protocols bgp group group-name] hierarchy level as follows:

[edit protocols]

bgp {

    group group-name {

        type internal;

        local-address ip-address; 

        family family-type {

            unicast;

        }

        neighbor ip-address;

    }

}

The IP address in the local-address statement is the address of the loopback interface (lo0) on the local PE router. The IBGP session for the VPN runs through the loopback address. (You must also configure the lo0 interface at the [edit interfaces] hierarchy level.)

The IP address in the neighbor statement is the loopback address of the neighboring PE router. If you are using RSVP signaling, this IP address is the same address you specify in the to statement at the [edit mpls label-switched-path lsp-path-name] hierarchy level when you configure the MPLS LSP.

The family statement allows you to configure the IBGP session for either Layer 2 VPNs and VPLS or for Layer 3 VPNs. To configure the IBGP session for Layer 2 VPNs and VPLS, include the family statement at the [edit protocols bgp group group-name] hierarchy level:

[edit protocols bgp group group-name]

family l2vpn {

    unicast;

}

To configure the IBGP session for Layer 3 VPNs, configure the family statement at the [edit protocols bgp group group-name] hierarchy level:

[edit protocols bgp group group-name]

family inet-vpn {

    unicast;

}