asked on

Spanning Tree MST Topology / excessive changes

Debug info attached

I have configured a HP Procurve 3500 YL with the following Spanning Tree config:

spanning-tree
spanning-tree instance 2 vlan 109-285
spanning-tree instance 2 priority 0
spanning-tree priority 0

This config works well on other switches on our WAN. However, in this instance (only this switch), the topology count changes several times a minute. I believe it has something to do with ports 19 and 23. Each is configured with a single vlan and are directly connected to a Cisco 2960 switch. All others ports are connected to HP Aruba switches.

Ideas?
spanning-tree-debug

ASKER CERTIFIED SOLUTION

Craig Beck

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

Raymond Norton

ASKER

Both ports are connected to a Cisco 2960
Port 19 (vlan 100) is connected to port 1 and port 23 (vlan 266) is connected to port 47

The Cisco is configured as pvst, which is a problem.

Looks like I need help to configure both the Procurve and Cisco to use mst

Benjamin Van Ditmars

Why 2 uplinks. spanningtree will still detect you have a loop. just create a trunk port with both vlans on both sides.

Raymond Norton

ASKER

It should not detect a loop if a single, unique vlan is configured per port. We are doing vlan translation for a number of our schools (long story) and require individual ethernet ports for each vlan to do this.

Craig Beck

Can you show the config for the ports at each end, please?

Raymond Norton

ASKER

I resolved the issue by finding a loop via lldp info on one of the school switches and creating an mst region for all vlans, except voip. I left the Cisco config in place to manage spanning-tree for those vlans.