synchronization

cdad2000

What's the big deal with route synchronization?

nice343

are you talking about bgp synchronization? can you be more specific?

dtlokee

BGP synchronization was intended to prevent black holes in your network because you may have BGP routes that are not know to the non-BGP speakers on your network. The intent would be that a BGP route cannot be advertised to another iBGP peer until it is know by the IGP thus preventing any black holes. Since it is impractical to redistribute an Internet routing table into an IGP like OSPF (ask anyone who has accidently done this!) synchronization is no longer practical but it means all routers in the transit path must run BGP (or in many cases a MPLS core but that's beyond the scope of the question)

cdad2000

OKay,
\\And that is why a full-mesh network not required?

dtlokee

Full mesh is a different requirement of iBGP. All iBGP speakers use a concept similar to split horizion in RIP where they will not advertise a prefix learned from one iBGP peer to another iBGP peer (but they will advertise it to a eBGP peer). This requires all iBGP peers to be fully meshed or use route-reflectors or BGP confederations (this is becoming less common). When you use a route reflector it will send the prefixes from one iBGP peer to be sent (reflected) to another iBGP peer thereby removing the requirement of a fully meshed network.

cdad2000

Your the MAN!!!