R&S Quick Notes – BGP

BGP

• When using Communities, don't forget “neighbor send-community”
• Know your attributes and the direction which applied, when to used what.
• “aggregate address” needs a more specific prefix in the BGP table for aggregate to be advertised.
• Synchronization issue has 3 solutions, 1- Load BGP on all transit routers, 2- GRE tunnel, 3- Redistribution BGP>IGP.
• “no bgp nexthop trigger” – Disables next-hop tracking between scanner intervals.
• “no bgp fast-ext-fallover” – Force the router to wait for the dead-timer to expire, before generating notification messages , when a connected peer goes down.
• “neighbor fall-over” – Will check neighbor connenctivity between scanner intervals, aka BGP Fast Peering.
• Only the Holdtime is sent in update-msg. Two neighbors will use the lowest holdtime and then calculate the keepalive from that.
• Know your Regular Expressions
• Know the difference between Peer-Groups and Peer-Templates