 | Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |
A Border Gateway Protocol (BGP) AS path is a path to a destination. An AS path consists of the AS numbers of networks that a packet traverses if it takes the associated route to a destination. The AS numbers are assembled in a sequence, or path, that is read from right to left. For example, for a packet to reach a destination using a route with an AS path 5 4 3 2 1, the packet first traverses AS 1 and so on until it reaches AS 5, which is the last AS before its destination.
You can define a match condition based on all or portions of the AS path. To do this, you create a named AS path regular expression and then include it in a routing policy.
The following sections discuss the following tasks for configuring AS path regular expressions and provides the following examples:
| Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |