Configuring Inter-Provider Vpn Option C - 3Com S7906E Configuration Manual

For inter-provider VPN option B, two configuration methods are available:
Do not change the next hop on an ASBR. With this method, you still need to configure MPLS LDP
between ASBRs.
Change the next hop on an ASBR. With this method, MPLS LDP is not required between ASBRs.
Currently, only the second method is supported. Therefore, MP-EBGP routes will get their next hops
changed by default before being redistributed to MP-IBGP. On conventional BGP, however, EBGP
routes to be advertised to IBGP do not have their next hops changed by default. If the next hops need to
be changed to the local addresses, you can configure the peer { ip-address | group-name }
next-hop-local command. For information about the command, refer to BGP Configuration in the IP
Routing Volume.

Configuring Inter-Provider VPN Option C

Configuring the PEs
You need to establish ordinary IBGP peer relationship between PEs and ASBR PEs in an AS and
MP-EBGP peer relationship between PEs of different ASs.
The PEs and ASBR PEs in an AS must be able to exchange labeled IPv4 routes.
Follow these steps to configure a PE for inter-provider VPN option C:
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
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
peer { group-name |
ip-address } enable
peer { group-name |
ip-address }
next-hop-invariable
1-37
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.