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how to find where the topology changes are happening?


I have about 130 switches in 8 rings topology, all connected to one core switch.
looking to the "Number of Topology Changes" I am finding high numbers, but I cannot figure out where this changes is being happened.

the used switches: X440, BD8806
Network cabling: 10G FO.

any way to figure out?

6 replies

When you go to the core, type in

show stpd "s0" ports counters.

What output do you see?
Jeremy Gibbs wrote:

When you go to the core, type in

show stpd "s0" ports counters.

What output do you see?

No such an argument!

Hi Yusuf,

There's a log message that can be added to the switch for that.

Here is the article on the subject:
https://gtacknowledge.extremenetworks.com/articles/Q_A/Is-there-an-EMS-log-filter-that-can-be-used-t...

Thanks!
Brad
Brad wrote:

Hi Yusuf,

There's a log message that can be added to the switch for that.

Here is the article on the subject:
https://gtacknowledge.extremenetworks.com/articles/Q_A/Is-there-an-EMS-log-filter-that-can-be-used-t...

Thanks!
Brad

Thanks Brad,

should I use it on all switches or deploying on core is enough?

Thanks
Yusuf
Brad wrote:

Hi Yusuf,

There's a log message that can be added to the switch for that.

Here is the article on the subject:
https://gtacknowledge.extremenetworks.com/articles/Q_A/Is-there-an-EMS-log-filter-that-can-be-used-t...

Thanks!
Brad

As long as the core is participating in all of the STP domains, I would put it there. That will likely give you the notification you need.
Userlevel 3
Hi Yusuf,

Adding on to output of "show stpd ". Check the information in the field "Topology Change initiated locally on Port". This gives an idea as to where to start looking for in the switch.

Also, the logs can give you an idea if there had been any port flap seen in STP configured port that might have also caused the TCN to be generated by the switch.

Just a word of information, if the STP is configured for auto-bind ports, please configure STP edge on the host connecting ports to aviod the unnecessary generation of TCN.

Thank You,

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