iBGP Split Horizon – When an iBGP speaker learns of an iBGP Prefix it will not send the prefix to another iBGP speaker.
This means you will need to configure either a full mesh of iBGP peerings or use a function like route reflection or confederation to work around this rule.
eBGP Peering – Peering between different Autonymous Systems.
eBGP multi-hop – Used whenever you want to peer between loopback addresses between eBGP peers.
eBGP Multi-hop Lab
Configure the BGP topology given in the diagram.
All peering should be formed between loopback addresses.
Do not form an iBGP peering between R2 and R3.
Allowed to create static routes in AS 400 and AS 500 if needed.
