Even though the Cisco auto-negotiation for duplex selection works perfectly most of the times, however in some instances, a Cisco device is unable to detect the duplex mode and it may result in a duplex mismatch. This could results in a collision in the network. Therefore, to fully utilize the bandwidth and the capacity of the switch, it is a good practice to hard-code the speed and duplex on the Cisco devices.

In this lab, we will configure the speed to 100 Mbps and the duplex mode to full. Duplex mode should be configured on both the switches. Now, to configure the duplex and speed, we will have to go into the specific interface on which we want to hard-code the duplex setting.

Full duplex


Lab Tasks

  1. Hard-code interface fastethernet 0/1 to both switches to full duplex.
  2. Hard-code Speed to 100 Mbps.

Lab Configuration

Task 1

Switch(config)#interface fastethernet 0/1

Switch(config)#duplex full

Task 2

Switch(config)#interface fastethernet 0/1

Switch(config)#speed 100