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New Member

DTP modes and combinations memorization

Is there an easy way to remember DTP modes and their combinations ,see the table at the middle of the link below :

http://www.cisco.com/warp/public/793/lan_switching/2.html

3 REPLIES
Purple

Re: DTP modes and combinations memorization

If you understand what each of the modes means, then there is absolutely no need to memorize the result of their combinations. Concentrate on getting an understanding of what each mode actually means and you should be able to figure out the effect of combining any two modes...

Paresh

New Member

Re: DTP modes and combinations memorization

Thanks Paresh.

The only thing that I could not figure out why with the combination below we won't have trunk ?

DTP mode nonegotiate DTP mode desirable not-trunking

Purple

Re: DTP modes and combinations memorization

Here's why....

The side configured as negotiate will operate the link as a trunk, regardless of what the other side is set to. However, it will not send out any DTP packets, since it's configured as nonegotiate. The side configured as desirable will only operate the link as a trunk only if the other end also wishes to operate as a trunk. Since the other end is configured to not send any DTP packets, this switch will conclude that it cannot operate the link as a trunk. Since one end is trunking and the other end is not, the overall effect is non-trunking.

Hope that helps - pls do rate the post if it does.

Paresh

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