STP changes...

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Hello all

On our network i see quite a few stp topology changes.
What can be causing a STP topology change?

Does the small 8 port switches that users tend to add to a network send
bpdu's? Can the cause any harm (should we enable portfast...?)?

Thank you for your thoughts...


Re: STP changes...
u can enable bpdu guard, port fast is probably better option since it wont
shut down the port when other's connect eqmpt.

you can change the priority on your root switch to something lower than
default and that should take care of the topology changes....


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Re: STP changes...
My root switch stays the same.
However i am curious as to what can cause what is mentioned as (5000)
"topology changes" when typing "show span tree vlan 1 detail"


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Re: STP changes...
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a topology change?

ports going up / down - have you got "portfast" turned on for user ports -
if not every PC reboot or move of a laptop will generate a topology

more serious issues would be about a flakey network - maybe a link in a loop
that isnt working reliably.
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it certainly doesnt help as they are unlikely to have statistics and logging
to help you track down a problem.
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find where they come from - start at the centre, note the stats and then
clear them.
trace outwards following the statistics.
try to correlate changes with a device, habit of a user etc.

run some pings at 1 sec intervals thru the suspect bits of the network and
see if you are losing packets or getting variable delays - if you have, then
you have a problem to track down.

rince and repeat anywhere else with the issue.

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Regards - replace xyz with ntl

Re: STP changes...
Thank you both !


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