Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

How to find out conflicted IP in a Switch

Hi all

If an Ip address conflict occurs ,Is there any way (command) to find out from the Switch , that the conflicted Ip address (PC) are connected to which port on that Switch .



Cisco Employee

Re: How to find out conflicted IP in a Switch

Hi Sudeesh,

There is no direct command which can let you the port number on a switch but definetely there is way. If you know the conflicting ip address then you can go to the first layer 3 device or first layer 3 hop for that network and do "sh ip arp " and get the mac address and once you get the mac address you can come back to that switch and run a command "sh mac-address-table address " and get the port detail.



*Pls rate all helpfull post

Re: How to find out conflicted IP in a Switch

Hi Sudeesh,

This is only possible if there was a ping initiated from that PC to the switch's IP address. In that case only the switch will maintain the ARP table for that host and looking at the MAC in the arp table you will be able to locate the PC's mac on the switchport.

Another way to do that is by using some freeware tool that can locate the mac-address of the PC's having the same mac. There is a tool "ccgetmacaddress" that you can download and by putting the IP address it will tell you the mac-address of the HOST. Once you have the Mac-address for the host you will be able to locate it on the switch by looking in the mac-address table.


-amit singh