Configuring Inter-As Option B - HP 10500 SERIES Configuration Manual

To configure inter-AS option A, complete the following tasks:
Configure basic MPLS L3VPN on each AS.
•
• Configure each ASBR-PE, taking the peer ASBR-PE as its CE.
In other words, configure VPN instances on PEs and ASBR PEs, respectively. The VPN instances on PEs
are used to allow CEs to access the network, and those on ASBR PEs are used to access the peer ASBR
PEs. For more information, see
In the inter-AS option A solution, for the same VPN, the route targets configured on the PEs must match
those configured on the ASBR-PEs in the same AS to make sure VPN routes sent by the PEs (or ASBR-PEs)
can be received by the ASBR-PEs (or PEs). Route targets configured on the PEs in different ASs do not have
such requirements.

Configuring inter-AS option B

For inter-AS option B, the following configuration methods are available:
Do not change the next hop on an ASBR. With this method, you still must configure MPLS LDP
•
between ASBRs.
Change the next hop on an ASBR. With this method, MPLS LDP is not required between ASBRs.
•
The device supports only the second method. Therefore, MP-EBGP routes get their next hops changed by
default before being redistributed to MP-IBGP. However, normal EBGP routes to be advertised to IBGP do
not have their next hops changed by default. To change the next hop to a local address, use the peer
{ ip-address | group-name } next-hop-local command. For more information about the command, see
Layer 3—IP Routing Configuration Guide.
To configure inter-AS option B on ASBR PEs:
Step
1. Enter system view.
2. Enter interface view for the
interface connecting to the
remote ASBR-PE.
3. Configure the IP address of
the interface.
4. Return to system view.
5. Enter BGP view.
6. Enter BGP-VPNv4 subaddress
family view.
7. Disable route target based
filtering of VPNv4 routes.
In the inter-AS option B solution, the ASBR PEs must maintain all VPNv4 routing information and advertise
the information to peer ASBR PEs. In this case, the ASBR PEs must receive all VPNv4 routing information
without performing route target-based filtering.
In the inter-AS option B solution, for the same VPN, the route targets for the VPN instances on the PEs in
different ASs must match.
"Configuring basic MPLS
Command
system-view
interface interface-type
interface-number
ip address ip-address { mask |
mask-length }
quit
bgp as-number
ipv4-family vpnv4
undo policy vpn-target
263
L3VPN."
Remarks
N/A
N/A
N/A
N/A
N/A
N/A
By default, a PE filters received
VPNv4 routes by route targets.
The routes surviving the filtering
are added to the routing table, and
the others are discarded.