set as-path prepend


set as-path prepend <AS> <AS>...

no set as-path prepend <AS> <AS>...


Prepends the list of the configured AS numbers to the AS Path attribute of the routes. To ensure that the AS path conforms to standards, the local AS is prepended after this command is executed.

The no form of this command restores the default behavior of not modifying the AS Path attribute list.

Command context



<AS> <AS>...

Specifies the AS numbers to be prepended from the AS Path attribute of the route.


Administrators or local user group members with execution rights for this command.


Configuring a set clause in the route map to prepend the AS from the AS Path attribute of the route:

switch(config)# route-map GlobalMap permit seq 11
switch(config-route-map-GlobalMap-11)# set as-path prepend 1
switch(config-route-map-GlobalMap-11)# no set as-path prepend 102

The no form of the command deletes the entire list of AS-Path prepend configuration regardless of the parameter list. In this example, the no form command would result in deletion of all the three AS numbers that were earlier configured.