BGP: prefer locally/self originated paths
I'm having a hard time wrapping my head around #3 (or #4, depending on whether you consider "reachable next hop") in the path selection algorithm. Some sources cite "locally" as being local to the BGP speaker in question, while others cite it as being local to the AS/confed, originated via a netowrk statement or aggregate. I have to admit I'm kind of fuzzy on iBGP in general, so that may be part of the issue - I tend to view it as "last recourse" for any local routing since obviously just making it into the BGP table doesn't gurantee making it in to the routing table. My simplistic view of iBGP is that it's mostly useful for telling BGP speakers which exit to use when *leaving* the local AS, so it's surprising to me that local AS announcements would factor in towards the top of the list. Can anyone either point me to some good documentation/discussion of this point, or explain why this would land as #3 on the path selection list?
Sorry in advance if this is blindingly obvious and I'm just missing it.