Configuring The As_Path Attribute - HP 6125XLG Configuration Manual

Step
4. Specify the router as the next
hop for routes sent to a peer
or peer group.

Configuring the AS_PATH attribute

Permitting local AS number to appear in routes from a peer or peer group
In general, BGP checks whether the AS_PATH attribute of a route from a peer contains the local AS
number. If yes, it discards the route to avoid routing loops.
In certain network environments (for example, a Hub&Spoke network in MPLS L3VPN), however, the
AS_PATH attribute of a route from a peer must be allowed to contain the local AS number. Otherwise, the
route cannot be advertised correctly.
To permit the local AS number to appear in routes from a peer or peer group and specify the appearance
times (IPv4):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN
instance view.
3. Enter BGP IPv4 unicast
instance view or BGP-VPN
IPv4 unicast instance view.
4. Permit the local AS number to
appear in routes from a peer
or peer group and specify the
appearance times.
To permit the local AS number to appear in routes from a peer or peer group and specify the appearance
times (IPv6):
Step
1. Enter system view.
2. Enter BGP view or BGP-VPN
instance view.
Command
peer { group-name |
ipv6-address } next-hop-local
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
ipv4-family [ unicast ]
peer { group-name | ip-address }
allow-as-loop [ number ]
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
201
Remarks
By default, the router sets itself as
the next hop for routes sent to an
EBGP peer or peer group, but does
not set itself as the next hop for
routes sent to an IBGP peer or peer
group.
Remarks
N/A
N/A
N/A
By default, the local AS number is
not allowed in routes from a peer
or peer group.
Remarks
N/A
N/A