HP 6125XLG R2306-HP 6125XLG Blade Switch Layer 3 - IP Routing Configuration Gu - Page 214

the router to advertise a fake AS number 2 to its EBGP peers so that the EBGP peers still think that Router A is in AS 2. To advertise a fake AS number to a peer or peer group (IPv4): Step 1. Enter system view. 2. Enter BGP view or BGP-VPN instance view. Command system-view • Enter BGP view: bgp as-number • Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name 3. Advertise a fake AS number to peer { group-name | ip-address } a peer or peer group. fake-as as-number Remarks N/A N/A By default, no fake AS number is advertised to a peer or peer group. This command applies to only EBGP peers or EBGP peer groups. To advertise a fake AS number to a peer or peer group (IPv6): Step 1. Enter system view. 2. Enter BGP view or BGP-VPN instance view. Command system-view • Enter BGP view: bgp as-number • Enter BGP-VPN instance view: a. bgp as-number b. ip vpn-instance vpn-instance-name 3. Advertise a fake AS number to peer { group-name | a peer or peer group. ipv6-address } fake-as as-number Remarks N/A N/A By default, no fake AS number is advertised to a peer or peer group. This command applies to only EBGP peers or EBGP peer groups. Configuring AS number substitution IMPORTANT: Do not configure AS number substitution in normal circumstances. Otherwise, routing loops might occur. To use BGP between PE and CE in MPLS L3VPN, VPN sites in different geographical areas should have different AS numbers. Otherwise, BGP discards route updates containing the local AS number. If two CEs connected to different PEs use the same AS number, you must configure AS number substitution on each PE to replace the AS number in route updates originated by the remote CE as its own AS number before advertising them to the connected CE. 203