STP Disabled on HP 5800 w/ Cisco 2960 Connected

[jeff6strings]

I inherited the infrastructure below which is a Cisco 2960 switch and an HP 5820 switch connected via port-channel/link aggregation trunks. STP PVST is configured on the 2960 and STP is disabled on the 5820. The two trunk ports on the 2960 (G1/0/1, G1/0/2) are both in the Desg FWD state for all VLANs and in addition to STP turned off on the 5820 I suspect we have a loop. I also believe the 5820 should be root since it has the default GW switch virtual interfaces for all the VLANs.

I appreciate any feedback.

Jeff

[Jon Marshall]

As long as the connection is a port channel why would there be a loop ? Are there any symptoms you are seeing ?

Usually the L3 switch with the SVIs is root but it doesn't have to be, really depends on the topology.

Jon

[jeff6strings]

Jon,

I wasn't sure there would be a loop especially since there is a configured EtherChannel and I don't think I've ever worked with a switch without spanning tree. 

The only problem we have is the 2960 interface averages 6 -8 Million discards a day as I think the 2960 can't handle being used as as data center switch. 

The other question/problem I have is we plan on connecting a Nexus 9K to the HP 5800 keeping the HP switches as the default GW (for now). The 9K is configured with MST mode as the HP's by default support that mode even though STP is off. If we connect the 9K to the HP I don't think the 2960 will be root since the HP is not running STP but I'm on the fence to enable it on the HP.

Greatly appreciate your help.
Jeff

[Jon Marshall · Accepted solution]

Jeff

Etherchannel is seen as a single link so even without STP there should be no loop although personally I would always enable STP in case of mishaps.

The 2960 is most definitely not suited to it's current purpose :)

If you are connecting another switch and it was up to me I would want to enable STP on all switches assuming the HP can run a version of STP that is compatible.

Do you know if they can ?

Jon

[jeff6strings]

The HP 5820 stack support MST which I will have to enable and configure and the Nexus 9K is already configured with MST. The 2960 currently has PVST but supports MST.

I intend to connect the 9K to the 5820 with vPC on the 9K side and lag on the 5820.

Thanks again.

Jeff