Re: MAC to IP address

ganesh_nagar · ‎04-02-2002

Hi

can any one tell me how to find a IP address of a windows machine/network device using its MAC address

thanks in advance

Ganesh

jldediego · ‎04-02-2002

What you want is a RARP request, but for that you need a RARP server inside your ethernet collision domain.

Have a look at this:

http://www.webopedia.com/TERM/R/RARP.html

ganesh_nagar · ‎04-02-2002

No I am not asking for RARP server, i have collected the mac address table from the cisco switch, Now i want to find out all the IP addresses for the collected MAC addresses. Is there any way to do it?

Ganesh

jldediego · ‎04-02-2002

Hi again.

Using 'sh arp' at the cisco switch sould give you the mac-ip cache table.

Any way the complete arp table sould be at the dhcp server if you have it. Just enter 'arp' with the operating system dependent options (usually arp -a).

Maybe there is a command for the switch to do this, but I hope this help in any case.

fullerms · ‎04-04-2002

This command should give the IP address for a given MAC adddress

sh ip arp H.H.H

Of course, tools will automate the process and save you a lot of time.

timstewart · ‎04-02-2002

There are multiple ways you can do this:

1) Send a reverse arp frame to the client, at which point the client should respond back with it's IP address (you will need to manually create the RARP or use a pre existing rarp client/server software tool)

2) If you know the default gateway for the client the issue a "show arp" on the gateway. This will give you the arp cache entry.

3) If DHCP is used then you can look at hte DHCP database to find the mapping

4) If you know where the device is located then place a sniffer on the wire to capture frames from that device.

Tim

ganesh_nagar · ‎04-02-2002

hi tim,

thanks for your information. I will try this.

can you let me know any sniffer tool?

Thanks

Ganesh

timstewart · ‎04-02-2002

The most popular windows based tools are:

http://www.ethereal.com/ (free)

http://www.sniffer.com/products/default.asp (not free)

ganesh_nagar · ‎04-02-2002

hi tim.

Thank you

Ganesh

jkemery · ‎04-02-2002

The best valued packet capturer for windows that I have found is Etherpeak from Wildpackets. I use it everyday and find it very usefull. Make sure you get Netsense with it if you purchase it.

http://www.wildpackets.com