MSTP configuration - adding last switch fails with lockup

[Jelte Veldstra]

Our LAN consists of six ProCurve 2650 and two ProCurve 2510-24G switches. These switches are stacked with one commander and seven members. All switches are linked using the highest portnumbers and schematically the current setup is like so:

|---|
| switch1
| |
| switch2
| |
| switch3
| |
| switch4
| |
| switch5
| |
| switch6
| |
| switch7
| |
| switch8
|-X-|

The X in the bottom of the schema represents a cut in the loop. Last weekend I tried implementing a MSTP configuration so I could close this loop and have basic redundancy added to this topology.

On all switches the same VLAN configuration is created and the uplink ports to other switches are configured with the default VLAN untagged and the other VLANs tagged.

When creating the MSTP config I had created an instance per switch and made each switch the root for one VLAN. Here's the MSTP config section of switch one:

spanning-tree
spanning-tree protocol-version MSTP
spanning-tree config-name "bzlan"
spanning-tree instance 1 vlan 1
spanning-tree instance 1 priority 0
spanning-tree instance 2 vlan 2
spanning-tree instance 2 priority 1
spanning-tree instance 3 vlan 3
spanning-tree instance 3 priority 1
spanning-tree instance 4 vlan 4
spanning-tree instance 4 priority 1
spanning-tree instance 5 vlan 5
spanning-tree instance 5 priority 1
spanning-tree instance 10 vlan 10
spanning-tree instance 10 priority 1
spanning-tree instance 16 vlan 16
spanning-tree instance 16 priority 1
spanning-tree priority 0


And here's the MSTP config section of switch 2:

spanning-tree
spanning-tree protocol-version MSTP
spanning-tree config-name "bzlan"
spanning-tree instance 1 vlan 1
spanning-tree instance 1 priority 1
spanning-tree instance 2 vlan 2
spanning-tree instance 2 priority 0
spanning-tree instance 3 vlan 3
spanning-tree instance 3 priority 1
spanning-tree instance 4 vlan 4
spanning-tree instance 4 priority 1
spanning-tree instance 5 vlan 5
spanning-tree instance 5 priority 1
spanning-tree instance 10 vlan 10
spanning-tree instance 10 priority 1
spanning-tree instance 16 vlan 16
spanning-tree instance 16 priority 1
spanning-tree priority 1

In a similar way the instance priority is set per switch so that all switches have priority 0 for one VLAN.

Now the issue is that as I setup MSTP on the switches one by one all seemed to go well until I reached the last one. I could enter the MSTP parameters (for this switch an exact copy of the previous switch (there are seven VLANs and eight switches), but when I tried enabling the MSTP configuration by entering "span" the switch would freeze and a power cycle of the switch was the only means to get it back online. It would come online with the MSTP parameters saved, but no spanning tree enabled.

All switches are loaded with the latest firmware available at the moment.

STP is a new area for me and I have done my best to read up on the subject. Unfortunately I have no idea how to troubleshoot from here. How could I work out where this configuration goes wrong or find out why the switch freezes?

Thanks in advance for your time.