Allied Telesis AR2050V, Справочник по командам, Страница: 1401 / 2824

C613-50186-01 Rev B Command Reference for AR2050V 1401
AlliedWare Plus™ Operating System - Version 5.4.7-1.x
R
OUTE
M
AP
C
OMMANDS
SET AS
-
PATH
set as-path
Overview Use this command to add an AS path set clause to a route map entry.
When a BGP update message matches the route map entry, the device prepends
the specified Autonomous System Number (ASN) or ASNs to the update’s AS path
attribute.
The AS path attribute is a list of the autonomous systems through which the
announcement for the prefix has passed. As prefixes pass between autonomous
systems, each autonomous system adds its ASN to the beginning of the list. This
means that the AS path attribute can be used to make routing decisions.
Use the no variant of this command to remove the set clause.
Syntax set as-path prepend < 1-65535 > [< 1-65535 >]...
no set as-path prepend [< 1-65535 > [< 1-65535 >]...]
Mode Route-map mode
Usage Use the set as-path command to specify an autonomous system path. By
specifying the length of the AS-Path, the device influences the best path selection
by a neighbor. Use the
prepend
parameter with this command to prepend an AS
path string to routes increasing the AS path length.
This command is valid for BGP update messages only.
Example To use entry
3
of the route map called
myroute
to prepend ASN
8
and
24
to the
AS path of matching update messages, use the commands:
awplus# configure terminal
awplus(config)# route-map myroute permit 3
awplus(config-route-map)# set as-path prepend 8 24
Related
Commands
match as-path
route-map
show route-map
Parameter Description
prepend
Prepends the autonomous system path.
<1-65535>
The number to prepend to the AS path. If you specify multiple ASNs,
separate them with spaces.