Scenario:
Field tech goes on-site for some server maintenance. Server1 is currently plugged into a switchport int fa 1/0/1. The tech has unplugged server1 and forgotten where it should go. Instead they accidentally plug Bob from HR's patch into switchport int fa 1/0/1. Now they are calling you needing you to sort this out - they have left the site so they are unable to plug Server1 back into the proper port and Bob is calling because he needs to do some work but his PC is not connected to the network!
