Cisco Switch Trunks and Dynamic Trunking Protocol

From NetworkChatter

Here is a table that represents the different modes a link can come up in based on the DTP/port settings on each end. I have added the Cisco IOS commands at the bottom to help you remember which command is used for each mode. I have added the old legacy "set" commands from the Cisco CatOS days (no used anymore) to help with the legacy terminology - ie. When trunking is "on" which refers to the old "set trunk x/x on" command.

Trunk Type	Dynamic Auto	Dynamic Desirable	Trunk	Access
Dynamic Auto	Access	Trunk	Trunk	Access
Dynamic Desireable	Trunk	Trunk	Trunk	Access
Trunk	Trunk	Trunk	Trunk	Not Recommended
Access	Access	Access	Not Recommended	Access
IOS Command	switchport mode dynamic auto	switchport mode dynamic desirable	switchport mode trunk	switchport mode access
Catalyst "set" Command	set trunk mod_num/port_num auto	set trunk mod_num/port_num desireable	set trunk mod_num/port_num on