09-05-2009 10:45 AM - edited 03-06-2019 07:36 AM
Hi!
My test lab works fine, but when I do a
"debug spanning-tree bpdu"
I never see bpdus of the root bridge in my logs.
I have tried it out with a C3750 and a C3550 as a root bridge, but it is always the same.
If any one could help me - that would be great! :-)
Best regards from Austria,
Silvia
09-05-2009 11:04 AM
Hello Silvia,
first of all great caution with this debug: never use it on production network.
I did and I was lucky to find someone to reboot the switch (a C4506) it has become unmanageable in a few seconds and also user traffic had started to be affected.
So use it only in a lab.
Some debug commands show only received packets of a certain protocol for example STP and the root bridge receives BPDUs only when a topology change happens.
do you see root bridge BPDUs on non-root bridge when using the debug?
Hope to help
Giuseppe
09-05-2009 12:11 PM
Hi Guiseppe!
Thank you for the answer and the hint!
But I am luckily in the lab.
That's exactly what I could see.
I see outgoing config bpdus from all switches (except the root).
As soon as Topology Changes happen - I see more.
So there is no way to change that? I was wondering, because there would be a further debug command "received" "send" that I didn't use.
When I see in the logs "Data 000000*" is this the received or the sent Data?
Cheers,
silvia
09-05-2009 12:34 PM
Hello Silvia,
I can only look at the debug command reference that you can find here:
Actually, it declares that both received and sent BPDUs should be seen in the debug output.
It also provides two options: transmit and receive.
So you have found a different behaviour on STP root bridge.
I would suggest to use STP commands to make different switches root bridges in different vlans and to see what happens.
Hope to help
Giuseppe
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