Configuring Inter-As Option C - HP FlexNetwork 10500 Series Configuration Manual

Step
12. Enable BGP to exchange
VPNv4 routes with the PE in
the same AS and the ASBR
in different ASs.
13. Disable route target filtering
of VPNv4 routes.

Configuring inter-AS option C

To configure inter-AS option C, perform configurations on PEs and ASBRs.
•
PE configuration:
Configure basic MPLS L3VPN, and specify the PE in another AS as an MP-EBGP peer. The

route targets for the VPN instances on the PEs in different ASs must match for the same
VPN. For information about PE configuration, see
Execute the peer ebgp-max-hop command to enable the local router to establish an EBGP

session to an indirectly-connected peer, because the PEs are not directly connected.
Specify the ASBR in the same AS as an IBGP peer, and enable BGP to exchange labeled

IPv4 unicast routes with the ASBR.
•
ASBR configuration:
Configure a routing protocol, and enable MPLS and LDP on the interface connected to an

internal router of the AS.
Specify the PE in the same AS as an IBGP peer, and the ASBR in a different AS as an

EBGP peer.
Enable BGP to exchange labeled IPv4 unicast routes with the PE in the same AS and the

ASBR in different AS.
Enable MPLS capability on the interface connected to the ASBR in another AS. There is no

need to configure a label distribution protocol, for example, LDP.
(Optional.) Configure a routing policy to determine which IPv4 unicast routes are advertised

to the IBGP or EBGP peer with MPLS labels.
In addition, configure BGP to advertise routes destined for a PE on PEs or ASBRs. For more
information, see Layer 3—IP Routing Configuration Guide.
Configuring a PE
To configure a PE for inter-AS option C:
Step
1. Enter system view.
2. Enter BGP instance view.
3. Configure the ASBR in the
same AS as an IBGP peer.
Command
peer { group-name | ipv4-address
[ mask-length ] } enable
undo policy vpn-target
Command
system-view
bgp as-number [ instance
instance-name ]
peer { group-name | ipv4-address
[ mask-length ] } as-number
as-number
213
Remarks
By default, BGP cannot exchange
VPNv4 routing information with a
peer.
By default, route target filtering is
enabled for received VPNv4
routes. Only VPNv4 routes whose
export route target attribute
matches local import route target
attribute are added to the routing
table.
"Configuring basic MPLS
Remarks
N/A
N/A
By default, no BGP peers exist.
L3VPN."