3Com MSR 50 Series Configuration Manual page 1493

To do...
Enter system view
Enter BGP view
Configure the ASBR PE in the
same AS as the IBGP peer
Enable the PE to exchange
labeled IPv4 routes with the
ASBR PE in the same AS
Configure the PE of another
AS as the EBGP peer
Enter BGP-VPNv4 subaddress
family view
Enable the PE to exchange
BGP VPNv4 routing
information with the peer
Configure the PE not to
change the next hop of a
route when advertising it to
the EBGP peer
Configuring the ASBR PEs
In the inter-provider VPN option C solution, an inter-provider VPN LSP is required,
and the routes advertised between the relevant PEs and ASBRs must carry MPLS
label information.
An ASBR-PE establishes common IBGP peer relationship with PEs in the same AS,
and common EBGP peer relationship with the peer ASBR PE. All of them exchange
labeled IPv4 routes.
The public routes carrying MPLS labels are advertised through MP-BGP. According
to RFC 3107 "Carrying Label Information in BGP-4", the label mapping
information for a particular route is piggybacked in the same BGP update message
that is used to distribute the route itself. This capability is implemented through
BGP extended attributes and requires that the BGP peers can handle labeled IPv4
routes.
Follow these steps to configure an ASBR PE for inter-provider VPN option C:
To do...
Enter system view
Enter BGP view
Configure each PE in the
same AS as the IBGP peer
Configuring Inter-Provider VPN
Use the command...
system-view
bgp as-number
peer { group-name |
ip-address } as-number
as-number
peer { group-name |
ip-address }
label-route-capability
peer { group-name |
ip-address } as-number
as-number
ipv4-family vpnv4
[ unicast ]
peer { group-name |
ip-address } enable
peer { group-name |
ip-address }
next-hop-invariable
Use the command...
system-view
bgp as-number
peer { group-name |
ip-address } as-number
as-number
1493
Remarks
-
-
Required
Required
By default, the device does
not advertise labeled routes to
the IPv4 peer/peer group.
Required
-
Required
Optional
Required only when RRs are
used to advertise VPNv4
routes, where the next hop of
a route advertised between
RRs cannot be changed.
Remarks
-
-
Required