Spanning tree configuration

[johannes.bink]

Hi,

I have four Cisco 2960-switches that I am going to configure Spanning Tree with. The topology looks like the picture I attach.

My question is how I can verify that I have configured it correctly. I need to know what ports are supposed to be Blocking and Forwarding?

Switch0 is the Root Bridge and Switch1 is the secondary Root Bridge.

I really would appreciate some guidance.

Thanks!

Johannes

[Jon Marshall · Accepted solution]

Johannes

If you want to verify which ports are blocking/fowarding

"sh spanning-tree vlan "

note that STP is done on a per vlan basis so if you have multiple vlans then you need to run this for each vlan although if you set the same STP root/secondary for all vlans then the same links should be forwarding/blocking.

Jon

[Richard Michael · Accepted solution]

Hi Johannes,

sh spanning-tree summary would give you the details, and sh spanning-tree vlan <>

If you still need filter the contents you can go ahead for ,

sh spanning vl | i VLAN|Root|the root

Thanks,

Ricky Micky

* Rate if this useful

[johannes.bink]

Thanks guys, those commands will help me! I just need to make sure that the correct ports are forwarding. On my Root Bridge (Switch0) all of the Trunk-ports are forwarding. Should it be like that?

[Jon Marshall · Accepted solution]

Johannes

Yes, on the root bridge all ports should be forwarding. The only time this wouldn't happen is if you actually connected 2 switch ports together on the root bridge, then it would have to block one but you generally don't do this

Jon

[Richard Michael · Accepted solution]

Hello Johannes,

All the ports in the root are should be forwarding, Designated ports - FWDING.. you are right

Thanks,

Ricky Micky

[johannes.bink]

Thats great Thanks for your help guys!

Regards,

Johannes