From: kasturi cisco (kasturi_cisco@hotmail.com)
Date: Thu Dec 18 2003 - 20:50:29 GMT-3
Steve,
Let me try to explain what I have learnt... not a guru on this.
The RR principle comes into play for the iBGP limitation - which is "a
route learnt from one iBGP peer wont be reflected to another iBGP peer".
Now this becomes a problem when we take the scenario like yours or even
in general when u want the route to be seen on every other router. To
overcome this problem u have 2 solutions...
1. Have a complete iBGP mesh which is iBGP from any router to any.
2. Use router reflectors which will reflect the routes. As the name
implies the RReflector reflects the route(s) it learns.
Now to understand this we need to know 3 rules of what/when/to whom the
RR reflects the routes.
1.A route from an external BGP speaker is advertised to all clients and
nonclient peers.
2.A route from a nonclient peer is advertised to all clients.
3.A route from a client is advertised to all clients and nonclient peers.
Hence, the clients need not be fully meshed
So using these 3 (knowns) try to work around.
So now coming to your case when u make R3 a RR and R2 and R4 its clients
then routes from R4 will go to R2 as it is a client (rule 3).
Now make R2 a RR with ONLY R1 as a client and R3 as non-client. So any
routes rx by R2 from R1 will go R3 as per rule above (rule 3)
R3 will send routes learnt from R2 to R4 as per rule 3.
R2 will send routes learnt from R3 to R1 as per rule 2.
HTH. Correct me or add if needed.
Good luck,
Kasturi.
------------------------------------------------------------------------
Get the best astro advice. See what the stars hold in store. Simply click
here.
This archive was generated by hypermail 2.1.4 : Sat Jan 03 2004 - 08:25:43 GMT-3