As you can see from Topology, the NBMA routers are all running iBGP, while our outlying router are running eBGP - It just got real! Now I know what you are thinking, "What if the physical interface connected to the Remote BGP peer goes down? What then smart guy? Just lose the Adjacency of that … Continue reading eBGP: Creating Neighbors using loopback interfaces, configuration examples, and explanation of BGP behaviors / concepts when it comes to loopbacks!
So my initial thought was to make R2 the iBGP Peer to R1 in AS 100, however I may want to use R4 also running on 15.x code to get into the mix here as we progess, so on R3 it goes! And a quick tidbit of knowledge to start things off: You cannot make … Continue reading BGP RID manual configuration, iBGP Peering with R3, a much briefer “show” command for verification, and important BGP behavior info for exam day!
From the BGP Intro, here are the points relevant to this post: BGP Peers in the same AS are iBGP (Internal) Peers BGP Peers NOT in the same AS are eBGP (External) Peers The underlying connection that forms BGP Peerings is connection oriented The connection runs on TCP port 179 BGP Adjacencies = BGP "Peerings" … Continue reading eBGP Peering basics reviewed, configuration example, BGP states explained from beginning to Established!
BGP is an internet protocol that allows groups of routers (called Autonomous Systems) to share routing information, so efficient loop free paths can be established, and that sounds exactly like what EIGRP already does so what is the need for BGP? I am glad I asked: BGP is an Exterior Gateway protocol that runs between … Continue reading BGP Intro: Comparison to EIGRP behaviors, Cisco Best Practices, and BGP Peering explained before the labs begin!