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disabling spanning-tree

How does one disable spanning-tree on a 3550 switch?  

Is it as simple as:

conf t
no spanning-tree
^Z

Or does it have to be disabled for every interface and vlan?

thx
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amlp
Asked:
amlp
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1 Solution
 
JFrederick29Commented:
Each VLAN runs an instance of STP so yes, you'll need to disable spanning tree per VLAN, although I would advise against it.  Any particular reason why you want to disable spanning tree?

no spanning-tree vlan 1
no spanning-tree vlan 2
no spanning-tree vlan 3
etc...
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amlpAuthor Commented:
yes.

1.  our topology doesn't really require it (or doesn't have to)

2.  the servers (10 of them, plus the workstations) we use this network for sends out "are-you-alives?" to each other at sub-1 second intervals (as near as we can tell.  It's an old, obsolete, closed-source app)  (don't ask 8) ).  If all the ports on the all of switches go into blocking (say, to re-configure spanning tree if one of the switches goes tu) as I understand this, it effectively shuts down the whole network until the spanning tree has restabilized, which can be up to a minute.  Unfortunately, if the -whole- network goes away for even a split second, then the servers all go apeshit, and finally all either lock up or reboot.   Given what they do, this has the potential of being a Very Bad Thing.  (hey, I didn't select this program ten years ago).  The one time it did happen (just recently, in fact 8) ) it was very ugly.  Not good for the blood pressure.

If we lose a switch, on the other hand, and the other switches all stay up, then the server redundancies take over, and everything works smoothly.
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JFrederick29Commented:
All ports will not go into blocking and you shouldn't lose connectivity on the network with STP enabled and a switch failure.  If it does become troublesome, you can disable it as shown above but you shouldn't even know STP is working in the background.  I would however, enable spanning-tree portfast on the server/workstation ports to speed up the STP transition to forwarding on the server and workstation ports.
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amlpAuthor Commented:
portfast is enabled on all workstation and server ports.

The only 'interconnects' between 3550's is via the gigabit fiber GBIC's.  Right now they are set up in a ring, specifically to take advantage of the spanning tree.  Those are the only ports not on portfast.

But what about the 'uplinkfast' and other similar options?  I would like to take advantage of anything to handle failures that I can, but not at the cost of something like the massive failures we had yesterday.
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JFrederick29Commented:
Enable uplinkfast to speed up convergance.  You may want to also enable backbonefast to speed up convergence of the spanning-tree when an indirect link failure occurs.
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amlpAuthor Commented:
followup:

We broke the ring turning the fiber connections from a ring to a bus, then went and 'no spanning-tree vlan 2' on our secondary vlan (which not coincidentally somewhat corresponds with the secondary physical lan) and watched the results.  Looked like all communications on vlan2 completely ceased.  after a few minutes I 'spanning-tree vlan 2' and comms came back.

What this tells me is I need to get someone smarter than I am to tell me what's going on.  Thank everyone for their help.
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