As-Path Regular Expression Examples - Cabletron Systems IA1100 User's Reference Manual

For example:
(4250 .*)
(.* 6301 .*) Means anything with 6301.
(.* 4250)
(. * 1104|1125|1888|1135 .*)
AS-path regular expressions are used as one of the parameters for determining which
routes are accepted and which routes are advertised.

AS-Path Regular Expression Examples

To import MCI routes with a preference of 165:
ip-router policy create bgp-import-source mciRoutes aspath-regular-
expression "(.* 3561 .*)" origin any sequence-number 10
ip-router policy import source mciRoutes network all preference 165
To import all routes (.* matches all AS paths) with the default preference:
ip-router policy create bgp-import-source allOthers aspath-regular-
expression "(.*)" origin any sequence-number 20
ip-router policy import source allOthers network all
To export all active routes from 284 or 813 or 814 or 815 or 816 or 3369 or 3561 to
autonomous system 64800.
ip-router policy create bgp-export-destination to-64800 autonomous-
system 64800
ip-router policy create aspath-export-source allRoutes aspath-regular-
expression "(.*(284|813|814|815|816|3369|3561) .*)" origin any
protocol all
ip-router policy export destination to-64800 source allRoutes network
all
Internet Appliance User Reference Manual
Means anything beginning with 4250.
Means anything ending with 4250.
Means anything containing 1104 or 1125 or 1888 or 1135.
Chapter 8: BGP Configuration Guide
103