How to speed up switch port startup

Switch ports could be connected to a variety of devices – other switches, routers, trunk ports, PC’s, or VoIP phones. Each of these devices has a different configuration. When a device is connected to a switch port, the switch will attempt to negotiate settings to match this device.

These negotiations include ones for the Dynamic Trunk Protocol (DTP) (to see if the connected device wants to setup a trunk) and Spanning Tree Protocol (STP) (Used to ensure that the connection will not cause a loop).

These both take time and will delay the ability of your device (such as a PC) to transmit and receive data from the network. Most of the time, you are connecting a PC to a switch and you just want to be able to use the network as soon as possible, right?

The commands I recommend enabling on all PC/laptop/printer switch ports include these (All configured in interface configuration mode):

switch#
switch#conf t
switch(config)#int fa0/21
switch(config-if)#switchport mode access
switch(config-if)#



switchport mode access: Sets the switchport into a non-trunking mode

switchport nonegotiate (optional): Disables the switchport from negotiating

spanning-tree portfast: Disables STP negotiations which speeds switchport forwarding (ensure this switchport only connects to an endpoint device)