IBGP Basics

IBGP works a little different from EBGP. There are a set of rules that apply to IBGP implementation which make IBGP different from EBGP. # 1. Routes learnt from One IBGP Peer cannot be advertised to another IBGP Peer. When two IBGP neighbors send update messages to each...
Continue reading

BGP Decision Process

When running BGP, the routes are exchanged between BGP peers using the UPDATE messages. UPDATE messages can send new routes or modified routes to a destination  and also withdrawn routes for a destination. These routes received in the update messages are kept separate from the IP routing table...
Continue reading

BGP Path Attributes

Path Attributes as the name suggests are the characteristics of an advertised BGP Route. BGP routing policy is set and communicated using the path attributes. Path Attributes fall into one of the two categories 1. Well-known Path Attributes 2. Optional Path Attributes Well-known: Meaning these attributes must be...
Continue reading

BGP Protocol Overview

BGP is as a Path Vector protocol and it forms unique unicast connections with each of its BGP speaking peers. BGP uses TCP Port 179, this free’s BGP from the overhead of lost packets retransmission, processing acknowledgements and sequencing, as all this is taken care by the transport...
Continue reading