DTP on trunk

sendalot

OCG says "Administratively configure access ports as access ports so that users cannot negotiate a trunk and disable the negotiation of trunking (no Dynamic Trunking Protocol [DTP] )."

Does this mean don't use DTP for anything or leave it on only for trunk ports?

Thanks.

mdomino

It's following the best practice that all switchports should be configured as their intended use of access or trunk. They're saying not to leave ports in dynamic desirable/dynamic auto. If you want a port to be a trunk then configure it as such with

config-if)# switchport mode trunk

sendalot

if I take off DTP off of everything. would trunking be affected?

EdTheLad

DTP Dynamic Trunking Protocol, it's link local, used to negotiate a trunk. If the link is an access link disable it, if the link is administratively set to trunk, disable it, if you intend to negotiate trunking, leave it enabled.
I recommend to set all trunk ports manually and disable DTP everywhere unless you have a specific requirement that needs trunks negotiated.