Spanning-Tree question... 2

[tklamb]

I have a large switched network running rstp and I want to add a 2940 with 1 uplink for a small layer 2 network. It was sent to me configured with pvst, I'm wondering if I even need spanning-tree running on this and should I just remove all config assoc with it. When I show spanning-tree this switch is showing as the root for protocol ieee, not sure if thats an issue or not.

Any assistance is appreciated, thanks.

 

[cisconooblet]

I still would enable rstp. That would keep all your switches running the same protocol. It will also put your access ports into portfast instead of you having to configure each interface in STP. You don't have a redundant link to that switch so its not going to help your convergence speed. I'd also change its priority so that you were sure it would not become root. (I'm assuming you don't want it to be). Thats just my 2 cents worth. Which aint much

 

[burtsbees]

Also, IMPORTANT: CHANGE THE VTP STATUS TO TRANSPARENT!!!

THEY DEFAULT AS SERVER!!! OTHERWISE, SAY BYE-BYE TO ALL YOUR VLANS!!!

:
wq!

/!!

 

[unclerico]

i second both nooblet and burt. ALWAYS ALWAYS ALWAYS before connecting any switch into your production environment ALWAYS change it to transparent even if it is a new switch right off the assembly line. You can change it back to a client or a server afterwards since doing so will change the revision number back to 0.

When I show spanning-tree this switch is showing as the root for protocol ieee, not sure if thats an issue or not

This may or may not be an issue depending on whether or not the rest of your spanning-tree topology is set up correctly. With that switch isolated from your network, it will show that it is the root since there's no other switches to exchange BPDU's with. Once you plug it in it will begin exchanging BPDU's. If you haven't explicity defined your primary and secondary root bridges you might have a problem, although chances are this switch that you're adding in is newer than the others and has a higher MAC address.

Spanning-tree is soooooo touchy that you MUST have a solid grasp of it before you start tinkering with it because you may cause your entire network to reconverge which means downtime regardless if it is 6 seconds or 50 seconds.

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[tklamb]

Thanks all for your replies. VTP is all set, was just a little worried when I did a show spanning tree and and saw this switch as the root.

Spanning-tree is finely tune on the rest of the network by my vendor so no issue there. With this switch having just a single trunk and 2 vlans I don't see why it even needs spanning tree at all.

 

[vipergg]

You need it because because if someone happens to loop 2 user ports together on that 2940 you can say goodbye to the rest of the network if you don't . If the vlans you are sending to that switch is setup as root on some other box they should not show as root on the 2940 , something not right there . It should show the root port as the link going to your uplink .