Extended Community Attributes

The extended community attribute provides a mechanism to label BGP routes. It provides two important enhancements over the standard community attribute:
The following two types of extended communities are available:

Although these two community types are generally used in L3 VPN network setup, you can also use them in a non-L3 VPN network to control the distribution of BGP routes.

BGP does not send either the extended or standard community attributes to their neighbors by default; you must use the configuration command configure bgp neighbor send-community.