Question about discovering a host on the LAN

[Leonardo Pena Davila]

Hello I have a network with multiple routers and switches, my question is if there is a way to know ecxactly where a host(server) is connected on the LAN. Example I want to know where the host with ip address 167.175.x.x is physically connected on the LAN. If I have a MAC-address there is way to accomplish the same task?

Thanks your help

Regards

Leo

[Georg Pauwen]

Hello,

an easy way to map your IP addresses and MAC addresses to the corresponding switchports is the following:

On your switch(es) execute the following command:

show mac-address-table (IOS)

or

show cam (CatOS)

This will give you a list of MAC addresses and their corresponding switchports.

Now on your router(s) execute the command:

show arp

This will give you the IP addresses in the router´s ARP table and their corresponding MAC addresses. Now match the three (IP address, MAC address, and switchport) and you have the desired result...

HTH,

Georg

[glen.grant]

If you only have the mac address then it's going to be harder , you can look in the arp tables and see if it's in the router which will give what address it's associated with and then you should be able to track it down from there . You should have good network maps which will help you also . If have the ip then you can tracroute it to the last hop and then look for the mac in the arp table and then look for that mac in the switch that it traced to .