4500X Upgrade - IOS 3.6.0E Stability

[Jeff Deibel]

We're preparing to deploy two 4500X's in VSS running IOS 3.4.4. I'm looking at upgrading to 3.6.0E for some of the new features including Dual-Active Fast Hello.

Is anyone out there running 3.6.0 that could provide some feedback regarding its stability?

[Leo Laohoo]

IOS XE version 3.6.0E is similar to IOS version 15.2(2)E.  

All I can say to you is this:  Test 3.6.0.E very well.  The IOS version 15.2(2)E is one of the most poorly coded IOS I've ever seen.  We "hit" or triggered 4 different Tracebacks/CPU spikes/crashes in the 4 hours of initial testing of 15.2(2)E.  When we hit seven, we stopped our testing.  

[amp512_nyph]

No experience with 3.6 train, have been running 3.5.3 for the most part, but there is no ISSU/eFSU upgrade path from 3.4 or 3.5 trains.. I tried in our lab environment on a pair of 4500-X running VSS on 3.5.3E code to 3.6.0E and it failed, but to Cisco's defense, Cisco hasn't published compatibility for  issu/efsu with VSS on this page so I won't take a chance: 

http://docwiki.cisco.com/wiki/Catalyst_4500/4900_series_ISSU_compatibility_matrix

[Leo Laohoo]

I rarely use ISSU/FSU/eFSU because this method seldom works.