Chapter 29
| IP Routing Commands
Border Gateway Protocol (BGPv4)
– 925 –
no-export – Routes with this community attribute are advertised only to
peers in the same autonomous system or to other sub-autonomous
systems within a confederation. These routes are not advertised to external
peers.
100-500 – Expanded community list number that identifies one or more
groups of communities.
expanded community-list-name – Name of expanded access list.
(Maximum length: 32 characters, no spaces or other special characters)
regular-expression – Regular expression indicating the community list
number or name
12
.
Command Mode
Global Configuration
Default Setting
No community lists are defined.
Command Usage
â—† Standard community lists are used to configure well-known communities or
community numbers. Expanded community lists are used to filter communities
using a regular expression.
â—† When multiple values are entered in the same community list, they form a
logical AND condition. When multiple values are configured in separate
community lists, the form a logical OR condition, where the first list that
matches a condition is processed.
â—† If the criteria specified for a community list is matched, then the
deny/permit condition is applied to the routing message.
â—† If a permit value is applied to a community list, the filter will implicitly deny
other community values.
â—† By default, the internet community is set with a route if no other communities
are defined.
â—† Use this command in conjunction with the neighbor send-community to filter
route updates sent to or received from a neighbor, or with the match
community route map command to implement a more comprehensive filter for
policy-based routing.