Korenix Technology Co., Ltd.
Industrial
Layer 3 Managed Ethernet Switch
_____________________________________________________________________________
Industrial Layer 3 Managed Ethernet SwitchUser Manual
Page: 780/1568
7.10.2.9 set as-path
To prepend one or more AS numbers to the AS path in a BGP route, use the
set as-path
command in
Route Map Configuration mode. This command is normally used to insert one or more instances of the
local AS number at the beginning of the AS_PATH attribute of a BGP route. Doing so increases the AS
path length of the route. The AS path length has a strong influence on BGP route selection. Changing
the AS path length can influence route selection on the local router or on routers to which the route is
advertised.
When prepending an inbound route, if the first segment in the AS_PATH of the received route is an
AS_SEQUENCE, as-path-string is inserted at the beginning of the sequence. If the first segment is an
AS_SET, as-path-string is added as a new segment with type AS_SEQUENCE at the beginning of the
AS path. When prepending an outbound route to an external peer, as-path-string follows the local AS
number, which is always the first ASN.
To remove a set command from a route map, use the
no
form of this command.
Syntax
set as-path prepend <as-path-string>
no set as-path prepend
Default Setting
None.
Command Mode
Route Map Config
Parameter
as-path-string:
A list of AS path numbers to insert at the beginning of the AS_PATH attribute of
matching BGP routes. To prepend more than one AS number, separate the ASNs with a space and
enclose the string in quotes. Up to ten AS numbers may be prepended.
