[c-nsp] BGP Peer Group drawbacks???

[Arie Vayner (avayner)]

I think this would provide a comprehensive overview:

Peer-Groups are a relatively old feature which was introduced to provide
two functions:
- Reduce BGP configuration by creating a "template" which can be
reapplied to multiple peers
- Reduce CPU workload for BGP updates, as all members in a peer-group
had the same egress policy, so an update had to be computed only once

As combining both functionalities into a single feature is a bit
restrictive (you have to have (mostly) the same config for all peers)
then this was basically split up:
- Dynamic Update Groups are built on the fly for BGP peers with similar
update (output) policies. This allows for CPU load reduction.
- Templates are used to build config templates to reduce configuration
complexity/clutter.

Arie


-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Bob Arthurs
Sent: Sunday, January 10, 2010 01:32
To: cisco-nsp at puck.nether.net
Subject: [c-nsp] BGP Peer Group drawbacks???


Hi all,

A colleague recently told me not to use BGP peer groups because he
insists that there a drawbacks to using them.

Does anyone know of any drawbacks to peer groups????



I dug the following up on the Cisco website:

"Cisco IOS Software Releases earlier than 11.1(18)CC have the
	 limitations described in this section. Failure to adhere to
these rules can
	 result in inconsistent routing.

 
	 If you use peer groups for clients of a route reflector, all
the
		clients must be fully meshed.

 
	 If you use an eBGP peer group, transit cannot be provided among
the
		peer group members.

 
	 All eBGP peer group members must be from the same subnet to
avoid
		non-connected next hop announcements.

 
  However, these limitations were removed starting with Cisco IOS
	 Software Releases 11.1(18)CC, 11.3(4), and 12.0. Only the
router on which the
	 peer groups are defined needs to be upgraded to the new code."






But the above limitations have now gone, so I can't think of what
drawbacks he might be refering to. 



Anyone know??


THanks in advance!







 		 	   		  
_________________________________________________________________
We want to hear all your funny, exciting and crazy Hotmail stories. Tell
us now
http://clk.atdmt.com/UKM/go/195013117/direct/01/
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/