3800 stack routing fails if a certain member is off line

[NikMiddleton]

Hi,  We have a pair of stacked 3800's connected to a pair of stacked 2920's.  We have inter vlan routing enabled with a different subnet on the 2920's.  This has been up an running for about 3 years without a problem.  A faulty stack cable needed to be replaced and the 3800 commander was inadvertently powered down.  At that point we lost all routing to the 2920 stack.  When the switch was powered up  routing was still down.  It was only when we swapped it to be it came back.  

The two stacks are connected using 10GB cables and are LACP.  Disconnecting either of them maintains the integrity between them as would be expected.

The firmware versions on all switches is KA.15.16.0010, ROM KA.15.09.  While there are newer versions of the , nothing in the release notes addresses this issue.

I'm stumped as to what this might be.  As this is a core piece of our network I have limited options in making changes in that we cannot have any real down time. 

[parnassus]

Really interesting...but...are you really sure that running a software version so old (KA.15.16.0010) hasn't a potentially (in)direct relationship with the issue your network experienced? Consider that latest KA.16.04.0019 for HP 3800 is just few weeks old (not few years old as the running one)...not to say that a similar approach should be considered also for HP 2920 stack.

If it isn't a bug...then it is something related to your specific configuration...so sanitized running configurations (HP 2920 stack and HP 3800 stack) would be of help to understand what happened.