I am using Catalyst 6500 in the test.
I wanted to examine details of the event, STP Debug was made Enable.
>logging buffer debug
>logging console debug
>debug spanning-tree event ( or ALL )
However, nothing is displayed.
nothing also even in the buffer.
(There is no problem in 2960/3750.)
Besides, should I set it?
※Version and more
（Does not use the VLAN Bridge(Cat3750:Fallback bridge))
(all port VLAN 1)
(Enable STP (Priority 4096) of VLAN 1)
Three machines are prepared and it connects it with the triangle.
It is a general composition.
Certainly, the state of STP can be seen from the command and the monitor port.
I want to know whether the Debug command can be used after it is understood.
It is a confirmation for that.
This is not guest's environment.
The availability of CPU goes up when executing it in guest's environment, and the possibility that the system hangs up is understood.
The Debug command was able to be used in old Version.
Moreover, it is possible to use it for HybridOS.
Present NativeOS alone cannot be used.
>debug spanning-tree all
Even if this is input, nothing is displayed as for Catalyst6500 alone.
>debug ip packet
The log comes out from this command.
Will this be a specification?
Or, is the command insufficient?
For native ios check out the below link for spanning tree debug command usage hope that clear you query
and debug ip packet Don't try it! This command can actually bring an entire production router/switch down.
However, when used properly, this command can be a very helpful. For example, you can use debug ip packet with an ACL.
If you want to view only traffic from host 126.96.36.199 to host 188.8.131.52 that was using port 80. Being very careful, you could see it using debug ip packet and an ACL.
AS400(config)# access-list 101 deny ip host 184.108.40.206 host 220.127.116.11 eq 80
AS400# debug ip packet detail 101
IP packet debugging is on (detailed) for access list 101
In this example, you have a rudimentary packet sniffer that gives information on TCP port number (src/dest), sequence number, ack, window, and flag information. In addition, this is for the entire device—not just a single interface.
Hope to help