A lot of Spanning Tree topology changes

[skt-tech]

Hello,

i hope someone can help me with our problem.

Our Network infrastructure has the following components:

- 2 HP 5406Rzl2 Core Switches
- Around 20 hp procurve switches (2510, 2610, 2620)
- We have on all switches BPDU-Protection on all "non switch uplink ports" enabled
- We have on all switches AutoAdminEdge and AdminEdge on all "non switch uplink ports" enabled
- spanning tree is RSTP
- one of the 5406Rzl2 is stp root

The Problem is, that we have a lot of spanning tree topology changes (around 300-500 per day). I checked al switches but there are no ports blocked by bpdu-protection.

I figured out, that on all switches there are a lot of  "blocked by STP" messages. Maybe someone can help me with this.

we have AutoAdminEdge and AdminEdge enabled. If i plugin a notebook on this ports there is anyway a timeout for around 3 seconds and this twice. If i look at the logs (logging -r) i can see that this port has follwing entrys:

I 07/11/17 08:08:09 ports: port 2 is now on-line
I 07/11/17 08:08:09 ports: port 2 is Blocked by STP
I 07/11/17 08:08:07 ports: port 2 is now off-line
I 07/11/17 08:07:57 ports: port 2 is now on-line
I 07/11/17 08:07:57 ports: port 2 is Blocked by STP
I 07/11/17 08:07:55 ports: port 2 is now off-line
I 07/11/17 08:07:53 ports: port 2 is now on-line
I 07/11/17 08:07:53 ports: port 2 is Blocked by STP

Is this a normal behavoir? I thought, if i enabled AdminEdge there is no STP check and why is this check performed twice?

Is there any other thing i can check why there are so many spanning tree topology changes?

Thanks for help.
Regards