In a perfect world, were everything is documented you will have a CMDB (Configuration Management Database) that will include all the details for every device in your environment. As every environment change and you may have forgot where did you plug in a server or a PC. Here list of steps you can use to find in which switch port is your PC or server connected. This procedure is based on Cisco Network IOS steps.
Steps to find PC or Server:
1. Login to your core switch performing routing
2. Find the IP to ARP information for your device.
sh ip arp xxx.xxx.xxx.xxx(IP Address of the PC or Server)
3. Find the port where the switch see the mac-address
sh mac address-table aaaa.bbbb.cccc
4. Check the port description to see if the port is an access port (client) or a trunk port
sh int description
5. If the port is an access port (client) then you found your port, if not then connect to the switch in the description field.