bop ext-community-list

Creates an configures a named extended community list

A BGP extended community is a group of routes sharing a common attribute, regardless of their network or physical boundary. By using a BGP extended community attribute, routing policies can implement inbound or outbound route filters based on the extended community tag, rather than a long list of individual permit or deny rules. A BGP extended community list is used to create groups of communities to use in a match clause of a route map. An extended community list is used to control which routes are accepted, preferred, distributed, or advertised.

The BGP extended community and standard community attributes are identical in function and structure, except that the former is an eight octet and the latter is a four octet attribute.

BGP extended community lists are used as match clauses in the following context:
  • BGP route map context. For more information, see match.
To navigate to the extended community configuration instance, use the following command:
<DEVICE>(config)#bgp extcommunity-list <EXTCOMMUNITY-LIST-NAME>
BGP Extcommunity List Mode commands:
  deny     Add a BGP Community List deny rule to specify extcommunity to
  no       Negate a command or set its defaults
  permit   Add a BGP Community List permit rule to specify extcommunity to

  clrscr   Clears the display screen
  commit   Commit all changes made in this session
  do       Run commands from Exec mode
  end      End current mode and change to EXEC mode
  exit     End current mode and down to previous mode
  help     Description of the interactive help system
  revert   Revert changes
  service  Service Commands
  show     Show running system information
  write    Write running configuration to memory or terminal

The following table summarizes the BGP extended community list configuration commands:
Click to expand in new window

BGP-Ext-Community-List Config Mode Commands

Command Description
deny (bgp-ext-community-list) Creates and configures a deny extended community (expanded or standard) rule
permit (bgp-ext-community-list) Creates and configures a permit extended community (expanded or standard) rule
no (bgp-ext-community-list) Removes an existing deny or permit extended community rule from this ext community list