Configuring PortFast
What is PortFast?

Spanning Tree PortFast causes an interface configured as a Layer 2 access port to transition from blocking to forwarding state immediately, bypassing the listening and learning states. You can use PortFast on Layer 2 access ports, which are connected to a single workstation or to a server, to allow those devices to connect to the network immediately, rather than waiting for spanning tree to converge. If an interface configured with PortFast receives a BPDU, then spanning tree can put the port into the blocking state utilizing a feature called BPDU guard.

CAUTION:

Because the purpose of PortFast is to minimize the time that access ports must wait for spanning tree to converge, it should be used only on access ports. If you enable PortFast on a port connecting to another switch, you risk creating a spanning tree loop.