H3C Technologies H3C S5560 Series Switches User Manual
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Disabling BGP from considering AS_PATH during optimal route selection
To disable BGP from considering AS_PATH during optimal route selection (IPv4):
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view or BGP-VPN
instance view.
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view:
a.
bgp as-number
b.
ip vpn-instance
vpn-instance-name
N/A
3.
Enter BGP IPv4 unicast
address family view or
BGP-VPN IPv4 unicast
address family view.
address-family ipv4 [ unicast ]
N/A
4.
Disable BGP from considering
AS_PATH during optimal
route selection.
bestroute as-path-neglect
By default, BGP considers
AS_PATH during optimal route
selection.
To disable BGP from considering AS_PATH during optimal route selection (IPv6):
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view or BGP-VPN
instance view.
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance view:
a.
bgp as-number
b.
ip vpn-instance
vpn-instance-name
N/A
3.
Enter BGP IPv6 unicast
address family view or
BGP-VPN IPv6 unicast
address family view.
address-family ipv6 [ unicast ]
N/A
4.
Disable BGP from considering
AS_PATH 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):
Step Command
Remarks
1.
Enter system view.
system-view
N/A