1.3.a Use IOS troubleshooting tools

1.3.a [i] debug, conditional debug

here is an example of a conditional debug for a capture of dtp with trunk mode on.

side note:  trunk mode on does not prevent dtp

ex cond debug

dtp will be prevented with the addition of:

dls1(config)#int f0/11
dls1(config-if)#sw nonegotiate