Cisco’s answer to connectivity delays is port fast. When port fast is enabled it can help reduce the time it takes a PC to get a response. For example, if a Pc usually receives a response from the network in 30 to 35 seconds, enabling port fast may cut it down to five or six seconds. A few reasons that port delays occur are if STP is enabled, if there is EtherChannel negotiation going on, or in the link speed/duplex negotiations are taking time. Many users will give up on attempts to connect even before the port has received the data packet. This is why enabling port fast is beneficial.

However, you must be careful when enabling port fast that the switch is only connected to one device as to avoid creating a network loop where information will get lost and keep circling. To enable port fast in the interface configuration mode first use the following command ciscoswitch(config-if)# switchport mode access  to force switchport mode to access. Then use this command ciscoswitch(config-if)# spanning-tree portfast  to enable port fast.

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Setting portfast on a cisco switch