Huawei Quidway S5600 Series Operation Manual page 373

Operation Manual – Routing Protocol
Quidway S5600 Series Ethernet Switches-Release 1510
Caution:
Using routing policy, you can configure the preference for the routes that match the
filtering conditions. As for the unmatched routes, the default preference is adopted.
If other conditions are the same, the route with the lowest MED value is preferred to
be the exterior route of the AS.
Normally , a BGP router checks the AS_Path attribute of the routes it receives. The
routes with their AS-Path attribute containing the local AS number are ignored to
avoid route loops.
You can configure virtual AS numbers as needed. Virtual AS number only applies to
EBGP peers. It conceals the actual local AS number. With a virtual AS number
configured in an AS, only the virtual AS number is visible to EBGP peers in other
ASs.
Use the command that changing the AS number in the AS_Path attribute in specific
network only. Improper configuration causes route loops.
Operation
Assign an
peer
AS number
as-number
for a peer
as-number
group
Terminate
the
peer { group-name |
connection
ip-address
between a
shutdown
peers/peer
group
Configure
that the
BGP update
packets only
carry the
pubic AS
number in peer
the AS_Path public-as-only
attribute
when a peer
sends BGP
update
packets to
BGP peers.
Huawei Technologies Proprietary
Command
Optional
group-name
By default, the local AS
number is not assigned to a
peer group.
} Optional
Optional
group-name
By default, a BGP update
packet carries the private AS
number.
5-28
Chapter 5 BGP Configuration
Description