April 15, 2010

BGP Next-Hop-Self Attribute

The BGP Next Hop Attribute is useful when passing routes received from an eBGP speaker and advertised to an iBGP speaker within the same Autonomous System. By default when a route is advertised to an eBGP outside of the AS, the router will make sure that the next hop attribute reflects its IP address… now imagine a route is advertised to an iBGP speaker and sourced into the BGP AS group. ... Read more

September 18, 2009

iBGP route reflectors

It is by default that all BGP peers within the same autonomous systems must peer with each other to form a full mesh in order for each peer to be able to advertise routes to its adjacent peer. “Disclaimer: BGP confederacies will not be tackled in this post” **For example ** if routerB learns a new route from routerA, it wouldn’t be able to advertise the learned route to routerC and routerC would only be able to learn the route from routerA. ... Read more