Tag Archive

BGP 4 Byte AS number Support

Published on July 6, 2012 By Daniel Rodriguez

Long time ago when BGP was under development, it was assumed that a 16 bit (2 bytes) number for the Autonomous System (AS) was more than enough (65536 AS Numbers), but the same situation as with IPv4 happened, we are running out of AS numbers “basically” at the same speed as IPv4 addresses. Strategies where […]

BGP TCP Session Buildup

Published on June 14, 2012 By Daniel Rodriguez

This is going to be a short post about a topic that sometimes people get confused with, and it’s how the BGP session gets established and the way that it can be properly filtered. Before any prefix information can be exchanged between two BGP application peers, a TCP session needs to be properly established. BGP […]

BGP Inject maps

Published on March 21, 2012 By Daniel Rodriguez

The BGP table right now is about 400k prefixes and it’s common to see network administrators and service providers summarizing or even filter prefixes that are way too specific to save resources  on the routers. You may come into a situation where you actually need to do the opposite, and that’s to send more specific […]

Configuring BGP Peer Templates

Published on May 13, 2011 By Daniel Rodriguez

Today I wanted to write about a nice optimization feature that we can use on our Cisco devices. I don’t know if this is inside the R&S Blueprint, but as vague and open as it is, you never know. BGP templates work kind in the same way as peer groups. But the last have some […]

BGP Confederations

Published on April 6, 2011 By Jose Miguel Huertas

One of the things to take into account when working with iBGP is the necessity of a full-mesh BGP topology. As we already know, BGP has the rule of not announcing to iBGP neighbors what has been learned from another iBGP peer, so that’s why we need to build a full-mesh BGP topology. As we […]

Configuring Multicast BGP

Published on April 1, 2011 By Daniel Rodriguez

Multicast BGP, oh that feared topic, I don’t know why but people tend to be afraid of Multicast BGP in ways that are simply not justified (OER/PFR – that’s a topic to be scared off), you just have to mention Multicast BGP out loud to see people screaming and running in circles, in reality the […]

BGP Route-Reflector Topologies

Published on March 31, 2011 By Jose Miguel Huertas

One of the peculiarities of BGP is its rule of not announcing to the iBGP neighbors what has been learned from another iBGP peer. BGP is a path-vector protocol. It’s very similar to a distance-vector protocol, but with the capability of managing thousands of prefixes in a very efective way, and with some interesting features, […]