Speed up DHCP delays with Portfast on Cisco switches and routers


You have noticed that it takes ages for client devices – like PCs, VOIP phones, even Xboxs – to get an IP address via DHCP. Sometimes an IP address is not given at all.

Here is how to speed up the DHCP process on Cisco switches and routers:


Simply select the range of ports you want to affect, then enable portfast:

Switch# conf t
Switch(config)# interface range fa0/3 - 48
Switch(config-if-range)# spanning-tree portfast


  1. Mike O'Connor says


    Technically you’re not speeding up DHCP here, you’re making a shortcut in spanning-tree. Without portfast, even a host with a statically assigned IP address would be faced with a delay before being able to join the network.