262can be received by the ASBR-PEs (or PEs). Route targets configured on the PEs in different ASs do not havesuch requirements.Configuring inter-AS option BFor 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 LDPbetween 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 bydefault before being redistributed to MP-IBGP. However, normal EBGP routes to be advertised to IBGP donot 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, seeLayer 3—IP Routing Configuration Guide.To configure inter-AS option B on ASBR PEs:Step Command Remarks1. Enter system view. system-view N/A2. Enter interface view for theinterface connecting to theremote ASBR-PE.interface interface-typeinterface-number N/A3. Configure the IP address ofthe interface.ip address ip-address { mask |mask-length } N/A4. Return to system view. quit N/A5. Enter BGP view. bgp as-number N/A6. Enter BGP-VPNv4 subaddressfamily view. ipv4-family vpnv4 N/A7. Disable route target basedfiltering of VPNv4 routes. undo policy vpn-targetBy default, PE filters receivedVPNv4 routes by route targets.The routes surviving the filteringwill be added to the routing table,and the others are discarded.In the inter-AS option B solution, the ASBR PEs need to maintain all VPNv4 routing information andadvertise the information to peer ASBR PEs. In this case, the ASBR PEs must receive all VPNv4 routinginformation 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 indifferent ASs must match.Configuring inter-AS option CTo configure inter-AS option C, perform proper configurations on PEs and ASBR PEs, and configurerouting policies on the ASBR PEs.Configuring the PEsYou must establish ordinary IBGP peer relationship between PEs and ASBR PEs in an AS and MP-EBGPpeer relationship between PEs of different ASs.
