SPANNING TREE PROTOCOL

[ZipperHeadMan]

Hi, I'm not the Cisco admin and know NOTHING for switching, can you help me?Recently Spanning Tree Protocol was enabled on the network, immediately I recognized a slow down in several network applications. SQL and Exchange time outs and loss of network connectivity are my main complaints. Does STP need to enabled on a non redundant star topology LAN? If STP is not configured correctly, will the symptoms I'm experiencing appear? The Cisco guy is adamant that he did not cause the issue, but I have to ask myself what changed? STP........Your comments would be appreciated!!!

 

[unclerico]

If all of the switches are Cisco then spanning-tree has been on the whole time. Perhaps it is something else??

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

 

[ATCal]

Spanning Tree is used to prevent loops in a network. The usual pain points are delays in network connectivity when rebooting while the ports get checked. Used to see problems with Netware, but not in an MS environment. Portfast remedies this for PC/Server ports.
I would agree with the previous poster that your problem probably lies elsewhere.

Al

 

[ZipperHeadMan]

A number of the swithes are Foundry.
This problem has occured in the past, with an SQL application. Once STP was disabled the app ran normally.

I'd appreciate this question being answered:
Does STP need to enabled on a non redundant star topology LAN?

Thank You.

 

[ATCal]

The short answer would be "no", but it seems as though you will be solving a symptom rather than the problem.

Al

 

[ZipperHeadMan]

I would agree but that's not my area to administer, nor to fix. But if I can gather info and "enlighten" minds, it might help me out in the long run.

 

[unclerico]

are you 100% certain that the topology is a non-redundant star?? how sustained are your problems?? was the loss of network connectivity just for a few seconds and then everything was ok or does it happen frequently?? the same goes with the performance problems.

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

 

[burtsbees]

Again, are the access ports all configured for portfast? Anything beyond convergence would be STP blocking ports, thus STOPPING the apps, not slowing them down. Spantree-portfast needs to be on every access port...

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[VinceWhirlwind]

The answer is "no, STP is not required".

However, from a risk-management perspective, having STP disabled leaves you open to the risk of somebody connecting one switchport directly to another on your network, causing a broadcast storm which could cause an almost-complete network outage.
In other words, STP is worth having on.

A few of things:
- enable RSTP instead of STP
- enable portfast on all edge ports
- make sure the "core" switch is configured with STP priority

 

[vipergg]

You also might want to check the Foundry setup and info to see if anything needs to be done as Foundry does not support per vlan spanning tree whereas cisco does . If you turn it off all it takes is one of those "experienced users plugging a cable from one switchport to another and you will have a fun day troubleshooting that .

 

[baddos]

I could bring a hub to your office and show you in under a minute why spanning tree is a requirement.

 

[imbadatthis]

A few of things:
- enable RSTP instead of STP
- enable portfast on all edge ports
- make sure the "core" switch is configured with STP priority

I would suggest MSTP instead, as some of the equipment is not cisco ...
that way you can have regions that look like a single spanning tree.

to your question, as others have said, no you dont need it.
although, and im writing out loud here, maybe your sql server's access is taking along time to respond due to the path STP chose to root ?
maybe changed the root switch to the closest one to your SQL server and see what happens ?

i recall one of my cisco exams had something very simliar to this as the scenario...