Site of Origin BGP Community Attribute

Site of Origin BGP Community Attribute

The site-of-origin (SoO) extended community is a BGP extended community attribute that is used to identify routes that have originated from a site so that the readvertisement of that prefix back to the source site can be prevented. The SoO extended community uniquely identifies the site from which a router has learned a route. BGP can use the SoO value associated with a route to prevent routing loops.

BGP per Neighbor Site of Origin Configuration

There are three ways to configure an SoO value for a BGP neighbor:

•BGP peer policy template—A peer policy template is created, and an SoO value is configured as part of the peer policy. Under address family IPv4 VRF, a neighbor is identified and is configured to inherit the peer policy that contains the SoO value.

•BGP neighbor command—Under address family IPv4 VRF, a neighbor is identified, and an SoO value is configured for the neighbor.

•BGP peer group—Under address family IPv4 VRF, a BGP peer group is configured, an SoO value is configured for the peer group, a neighbor is identified, and the neighbor is configured as a member of the peer group. 

BGP per Neighbor SoO Configuration 

Case Study 10: BGP Site of Origin 

http://www.shafagh.net/2009/10/ccie-sp-bgp-as-pe-ce.html