What is site of origin (SOO) in BGP

SoO for BGP is “linked” to CE-neighbor. So, when a prefix needs to be advertised to a CE neighbor, we check the SoO of the prefix with the SoO of the BGP neighbor. For anything else, it is linked to interface.

The configuration can be done in four ways

–“route-map in” on CE BGP neighbor command

–directly on the CE BGP neighbor command

–sitemap on VRF interface and redistribution of IGP (static) into BGP and IGP (static) routes point to this interface

–sitemap on VRF interface and network command

Using a route-map and setting different SoO’s for different prefixes coming from the same BGP neighbor does not make much sense, so I guess we were never bothered with the possible non-uniqueness in the configuration when looking at what a “site” is.