[c-nsp] Tuning HSRP timers for BGP routers

[Mack McBride]

What is your base CPU utilization?

Mack

-----Original Message-----
From: Matthew Huff [mailto:mhuff at ox.com] 
Sent: Wednesday, May 09, 2012 12:22 PM
To: Mack McBride; 'cisco-nsp at puck.nether.net'
Subject: RE: Tuning HSRP timers for BGP routers

That's the thing, we aren't getting any BGP events, just HSRP ones. The
netflow analysis don't show a high bandwidth utilization, that's why I was
looking at the BGP re-calc causing the HSRP hellos to drop.


----
Matthew Huff             | 1 Manhattanville Rd
Director of Operations   | Purchase, NY 10577
OTA Management LLC       | Phone: 914-460-4039
aim: matthewbhuff        | Fax:   914-460-4139


> -----Original Message-----
> From: Mack McBride [mailto:mack.mcbride at viawest.com]
> Sent: Wednesday, May 09, 2012 1:39 PM
> To: Matthew Huff; 'cisco-nsp at puck.nether.net'
> Subject: RE: Tuning HSRP timers for BGP routers
> 
> We use timers 2 and 6 on multiple sets of 6500s with a relatively large
> number of VLANs.
> The 6500 has a much less powerful CPU and seems to handle it ok.
> However, the 7200 is a software device so through traffic can have a
> major effect on CPU.
> It may be you have large high BW bursts during backups or something
> similar.
> You should probably do some correlation analysis before blaming the
> BGP.
> If you are getting that kind of BGP event on a nightly  basis you
> should probably talk to your provider.
> 
> LR Mack McBride
> Network Architect
> 
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
> bounces at puck.nether.net] On Behalf Of Matthew Huff
> Sent: Wednesday, May 09, 2012 7:46 AM
> To: 'cisco-nsp at puck.nether.net'
> Subject: [c-nsp] Tuning HSRP timers for BGP routers
> 
> We have a pair of Cisco 7204VXR with NPE-G2 running 15.1(4)M3. We are
> using default timers for the HSRP interfaces, and we are seeing nightly
> HSRP state changes. Not a lot, but 1-2 a night. This appears to only
> have started recently.  We are looking at logs, but I assume it's due
> to BGP cpu exhaustion. We don't see any L2 errors on the VLAN where the
> HSRP is running, so I don't think it's a physical problem.
> 
> 
> 
> What timers do people use for HSRP on BGP routers as a practice?
> Obviously we want the smallest timers that would be possible.
> 
> 
> 
> ----
> 
> Matthew Huff             | 1 Manhattanville Rd
> 
> Director of Operations   | Purchase, NY 10577
> 
> OTA Management LLC       | Phone: 914-460-4039
> 
> aim: matthewbhuff        | Fax:   914-460-4139
> 
>