Nimbus

Hi,

Is there any way I can find the IP address of a device on the LAN by using the MAC address? I think the divice has a static IP, but I don't know what it is. All I know is it's MAC address.

Any help?

Cheers

JV

If it's Windows you can use arp -a on the command line to display current IP/MAC address mappings.

ozzy

Not that I'm aware of - not directly anyway.

Only thing I can think of is use a packet sniffer (Etherreal works well) or use an IP scanner such as Languard. Both free tools and should track down the device.

Stefan

ozzy

JV, for that to work I think you need to have already ping'd the device. If it's a small IP range you could create a batch file and then try to match the MAC address in the ARP buffer.

ChrisB

Have you got a firewall or anything like that on your LAN?

My SonicWall Pro 3060 has an ARP cache which you can view the MAC <> IP mappings.

Nimbus

Tried arp but didn't work. Found a tool that scans the LAN and picks up IPs and MACs..

http://www.youngzsoft.net/cc-get-mac-address/

Scanning now..

dowser

Ethernet port of router on same subnet has this info in it's cache, assuming it's talking at all. You may need to ping across the entire subnet to wake it up.

Otherwise the switch will record the MAC to a port, trace the cable...maybe it doesn't have an IP address

Richard

Nimbus

Scaned the local subnet but could not find it. I suspect it's been re-set and has a different subnet now. Looks like I need to scan further...

ozzy

Some devices reset to a default IP address, or try using DHCP or just don't set one.

You may have to physically go get it and then work out how to reset the IP address manually.

Stefan

ozzy

BTW, what is the device?

If it's a print server, you can use other utilities to find it via broadcasts.

Stefan

Nimbus

It's a wireless Access Point.

Unless my PC is on the same subnet, it won't find it anyway. Correct? So how do I find what subnet it is on?

ozzy

If it's physically plugged into the same segment as your PC, but is configured with a completely different subnet, then NO you won't see it. You would need a router in between you and the device to do the subnet translation.

You would need to check other devices that may keep a record of it - firewall, switch, etc.. Other than that you would need to use a packet sniffer and try collecting broadcast packets from the device.

This all assumes it's configured on the same subnet and is physically attached to the same switches as your PC. OR you have a router in between.

Stefan

Nimbus

It's on the LAN. All ports are run through switches. There's a router, but that's to connect our LAN to the WAN. It dosn't route through that to get to me.

ozzy

OK, then NO you won't be able to see it then.

I would check the switches, but they might not show IP info - just MAC addressing.

Stefan

Nimbus

ar$e...

Thanks guys....