Spanning Tree - Problems

[kooper390]

Hi all!

I tried to deploy a network infrastucture with 6 switches (different vendors).

The Problem seems to be, that I have 2 root bridges. Ok I think one switch dont forward the BPDU, so two trees are established.

SW01 --- SW03 --- SW05 --- SW06
  |       |
SW02 --- SW04



Tree 1: SW01 to SW04
Tree 2: SW05 to SW06

The only default value I changed, was the bridge prio for SW03 to 4096. There is no BPDU or root bridge guard enabled.
If I make a new connection from SW05 to SW04 the storm beginns.


Some Ideas for troubelshooting?


Regards
Gerit

[IAN WHITMORE]

What make/model are your switches?

What STP protocol is running on each of them? And priority of each?

Regards.

[cadet alain]

Hi,

The Problem seems to be, that I have 2 root bridges

It's impossible, you can only have one root bridge per VLAN( PVST+,RPVST+) or for multiple VLANs( MST).

The only part where there could be a loop is  the left part unless if you have redundant links not bonded between sw5 and sw6.

If I make a new connection from SW05 to SW04 the storm beginns

Then STP is not doing its job.  Could you post output of following commands:

-sh span vlan X on sw3 where X is the vlan used for the connection

-sh int x/x switchport where x/x is interface on sw3 to sw 5

-sh int trunk on sw3

Regards.

Alain.

[kooper390]

Hi,

It's impossible, you can only have one root bridge per VLAN( PVST+,RPVST+) or for multiple VLANs( MST).

right! OK, it seems  that SW05 and SW03 don't speak to each other.

But I can ping in the entire network.

SW05 is a Brocade FLS648 and SW05 is a Intel SBCEGBESW1 (Blade Center).

SW03 have 4096 a prio.

And I hope I have everywhere turn RSTP on.

STP work for SW01 to SW04 and SW05 to SW06

Regards

Gerit

[cadet alain]

Hi,

just post the commands I asked please.

How do you know there is a storm? How do you detect it?

Regards.

Alain.