How to Locate a PC on the LAN

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Guest

I have a PC on my LAN that I know its IP and MAC address, but nothing else.
How can I locate it?

Thanks,
 
Ruteger said:
I have a PC on my LAN that I know its IP and MAC address, but nothing else.
How can I locate it?

Thanks,
Click to expand...


Do you mean physically locate it?
That's not easy.
It rather depends on the physical layout of the LAN.

First off, the IP address will tell you the subnet it's in, and if you have
multiple locations with multiple subnets, that narrows things down a bit.

But within one location, then it requires some manual work.

Try to gather some data on the machine:
Go to a command prompt and do an

nbtstat -A xx.xx.xx.xx ( where xx it the IP address. )

This will reveal the machine name and also the logged on users name.
Does this reveal anything illuminating?
Like the name of a department, room, or individual?

Do a 'net view' on it now, and see if the shares reveal anything.

Next , you need to trace it via the switch ports and the wiring.
It may be possible to log into the switches and query the port-to-MAC
address mappings.
You'd need to check the switch documentation.
A lower-tech way is to wait till a quiet time on the network ( like late
night ) and then ping the machine continually:

ping -t xx.xx.xx.xx
( Ctrl-C to stop it )

Then watch the lights on the switch.
From your machine, follow the flashing lights through any uplinks and other
switches till you find the port the machine is on. If there's too much
background chatter on the network to see clearly on the lights where your
pings are going, pull the network cables for a brief second if you need to
determine for sure the route, and observe the pings stopping. Then plug it
back in to resume the pings. That tells you you are on the correct path.
Follow this all the way to the far end. Then follow the cable from the
final switch port to the machine. It will likely go to a punch-down block
in a wiring closet, and with any luck, it will have a circuit number which
you can relate to a room & port number. I've done this before, and although
it's not elegant, it is effective.
 
Ron,

Thanks for the detailed response. No hostname, so I guess I'll try the
port/MAC switch trick or a continual ping.
 
If there is a DHCP and or DNS server you can extract the computer name from
its database. You can connect to it via Computer Management snap-in. You can
find its description and location in AD. If you know there is the user at
the console, then just use *net send* etc etc etc.
 
The best way to do is to have a database of your devices and it's location.
Sometimes it's better if you add which switch and port they are connected.
Also try to label each PC this way it's easier for you to find it instead of
going to each PC with it's device name. I agree with Ruteger, if you have a
cisco switch use this command "show mac-address-table | inc Fa" it will show
you all the mac address that are connected to each port. If you don't know
the mac yet use the nbtstat command. Hope this helps too..
 
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