Enterasys Networks X-Pedition XSR CLI - Manual (Page 310)

BGP Set Commands
6-114 Configuring the Border Gateway Protocol
Syntax
match ip next-hop access-list-number
Syntax of the “no” Form
The no form of this command removes the match next hop value:
no match ip next-hop access-list-number
Mode
Route‐map configuration: XSR(config-route-map)#
Default
No matching based on IP next hop.
Example
The following example sets the matching IP next hop to 10:
XSR(config)#access-list 10 permit 1.2.3.4
XSR(config)#route-map 1 permit 1
XSR(config-route-map)#match ip next-hop 10
BGP Set Commands
Route maps are comprised of sets of match and set commands. Match commands define the match
criteria for route maps. Routes that match all defined match criteria are processed via set
commands and those that do not match all of the defined match criteria in the route map are
ignored.
set as-path
This command increases the length of the AS‐path attribute for the BGP routing update messages
that meet the match conditions specified within a route map.
The length of the AS path attribute influences the BGP route selection process for destinations that
can be reached by means of multiple paths. AS path length is the only global BGP metric that you
can use to influence best‐path selection. A BGP speaker can influence the best path selection by a
peer by varying the length of the AS path.
If you do not set local preference or weight, AS path length determines which of multiple routes
are selected. Routes with longer autonomous system paths are preferred. To prefer a path, you can
pad the autonomous system path by prepending extra autonomous system numbers.
Syntax
set as-path prepend as-path-string
access-list-number The ACL to match, ranging from 1 to 199.
prepend Instructs the system to attach the as‐path‐string value to the AS path of the
route that matches the route map.