HPE FlexNetwork 5510 HI Series

253
Ignoring the AS_PATH attribute during optimal route selection
Step
Command
Remarks
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
vpn-instance-name
N/A
3. Configure BGP to ignore the
AS_PATH attribute during
optimal route selection
bestroute as-path-neglect
By default, BGP considers
AS_PATH during optimal route
selection.
Advertising a fake AS number to a peer or peer group
After you move a BGP router from an AS to another AS (from AS 2 to AS 3 for example), you have to
modify the AS number of the router on all its EBGP peers. To avoid such modifications, you can
configure 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 unicast/multicast address family):
Step
Command
Remarks
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
vpn-instance-name
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):
Step
Command
Remarks
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:
N/A