By using the show mac-address, sh arp, and sh lldp remote info commands, you can avoid almost all cable tracing.
First if you have a mac address of a client that you want to find the port of do this:
- Start by connecting to a switch and type 'show mac-address ######-##### (ie. sh mac-address 0017a4-d7fadf)
- This will return the port that the mac address is reported to be on.
- Check that another switch is not connected to that port by using 'sh mac (port#)' (ie. Sh mac a2)
- If you have just one mac address then you know the client is connected to that port. If you have a large list then another switch is most likely connected to that port. To look up the next switch, type the following command (only works with switches that support lldp, most nice switches do) 'show lldp info remote (port#) use the port number from before. (ie. Show lldp info remote a2)
- This will give you a description and IP address of the next switch in the chain. Use the same mac address command there to narrrow down the location of the port. Always check the mac addresses on the port (sh mac port#) to make sure you are not changing something that a switch is connected to.
If you know the IP address of the client you want to find the port of, you can ping the address from the switch (if it is on a vlan that has an IP in the clinet's subnet). This will refresh the arp table for that address, then you can type 'sh arp' to list the Ips, mac addresses, and ports. Remember to always check the mac addresses on the port to make sure there is only 1 (maybe 2) mac addresses on the port to verify that another switch is not connected to that port.
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