266
1. Enter system view.
system-view
N/A
2. Enter BGP instance view or
BGP-VPN instance view.
• Enter BGP instance view:
bgp as-number [ instance
instance-name ]
• Enter BGP-VPN instance
view:
a. bgp as-number
[ instance
instance-name ]
b. ip vpn-instance
N/A
3. Advertise a fake AS number
to a peer or peer group.
peer
{ group-name | ipv4-address
[ mask-length ] }
fake-as
as-number
By default, no fake AS number is
advertised to a peer or peer
group.
This command applies only to
EBGP peers or EBGP peer
groups.
To advertise a fake AS number to a peer or peer group (IPv6 unicast/multicast address family):
1. Enter system view.
system-view
N/A
2. Enter BGP instance view or
BGP-VPN instance view.
• Enter BGP instance view:
bgp as-number [ instance
instance-name ]
• Enter BGP-VPN instance
view:
a. bgp as-number
[ instance
instance-name ]
b. ip vpn-instance
N/A
3. Advertise a fake AS number
to a peer or peer group.
peer
{ group-name | ipv6-address
[ prefix-length ] }
fake-as
as-number
By default, no fake AS number is
advertised to a peer or peer
group.
This command applies only to
EBGP peers or EBGP peer
groups.
Configuring AS number substitution
not configure AS number substitution in normal circumstances. Otherwise, routing loops might
To use EBGP 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. This substitution can replace the AS number in route updates originated by
the remote CE as its own AS number before advertising them to the connected CE.