[c-nsp] Best practices for Cat6500

[Charles Spurgeon]

On Mon, Nov 01, 2010 at 05:20:52PM +0000, Phil Mayers wrote:
> >
> >I've read in another article (sorry, don't have the URL handy at the
> >moment but I think I saw in a PDF from cisco.com) that either implied
> >the use of NSF and HSRP together was OK thru config examples or
> >something or else explicitly stated the use of the to together is OK.
> >
> >Can anyone comment on this conflict? Also does this conflict with NSF
> >also apply to GLBP which can be configured in a way to behave similar to
> >that of HSRP? The second link above makes comment of GLBP but the first
> >one does not. Is GLBP newer than the first article?
> 
> We use NSF and HSRP just fine, and have done since 12.2(18)SXF. Although 
> it was "not supported" in that release, it seemed to cause no problems - 
> either the standby took over, or the master managed to "beat" the missed 
> HSRP packets.
> 
> 12.2(33)SXI adds support for SSO HSRP - see the release notes, and docs 
> here:
> 
> http://www.cisco.com/en/US/docs/ios/ipapp/configuration/guide/ipapp_hsrp.html#wp1103263

This isn't of any help on the 6500, but the Nexus 7000 supports an
interesting feature that addresses this issue called "HSRP extended
hold."

This kicks in during ISSU or NSF operations and sets the HSRP timer to
a default of 10 seconds:
http://www.cisco.com/en/US/docs/switches/datacenter/sw/5_x/nx-os/unicast/configuration/guide/l3_hsrp.html#wp1479547

-Charles

Charles E. Spurgeon / UTnet
UT Austin ITS / Networking
c.spurgeon at its.utexas.edu / 512.475.9265