Using Regular Expressions; As-Path Lists - Juniper JUNOSE 11.0.X IP SERVICES Configuration Manual

JUNOSe 11.0.x IP Services Configuration Guide
show ip extcommunity-list

Using Regular Expressions

You can use regular expressions when you define AS-path access lists and community
lists to more easily filter routes. A regular expression uses special characters often
referred to as metacharacters to define a pattern that is compared with an input
string.

AS-path Lists

For an AS-path access list, the input string is the AS path of the routes to which the
list is applied with the route-map or neighbor filter-list commands. If the AS path
matches the regular expression in the access list, the route matches the access list.
The following commands apply access list 1 to routes inbound from BGP peer
Example
10.5.5.2. Access list 1 uses a regular expression to deny routes that originate in
autonomous system 32.
44
Using Regular Expressions
You can specify both a route target community and a site-of-origin community
at the same time in a set clause without them overwriting each other.
Example
host1(config)#route-map 1
host1(config-route-map)#set extcommunity rt 10.10.10.2:325
Use the no version to remove the set clause from the route map.
See set extcommunity.
Use to display information about a specific extended community list or all
extended community lists.
Example
host1#show ip extcommunity-list
IP Extended Community List dresden1:
permit soo 10.10.10.10:15
IP Extended Community List bonn:
deny rt 12:12
See show ip extcommunity-list.
host1(config-router)#neighbor 10.5.5.2 remote-as 32
host1(config-router)#neighbor 10.5.5.2 filter-list 1 in
host1(config-router)#exit
host1(config)#ip as-path access-list 1 deny 32$