Cisco DTP (Dynamic Trunking Protocol) Negotiation

Hello Jesus

Beyond simply disabling the sending and receiving of DTP messages, it is important to disable DTP in situations where ports may inadvertently change modes. For example, a switchport with DTP enabled will remain in access mode if a PC is connected to that port. But what if a malicious user plugs in a switch on that port and causes the switchport to change to trunk mode? That user will now potentially have access to all the trunks configured on the switch.

So it is more of a security issue rather than simply eliminating DTP messages from the network.

I hope this has been helpful!

Laz