Rarp Utility

Is there a utility for NT/win95 that given a MAC address, will return the ip address??
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cerConnect With a Mentor Commented:
If the networkcard in question is NOT in the same subnet it is impossible. The IP-address is used to decide where the packets should be forwarded to.
If it is on the same subnet and you get packets from that networkcard you can isolate the IP-address by looking inside the packet. But the easiest way is the one suggested by bcook: Ping all IP-adresses in your subnet and create a list.

Again: You can not ping a MAC address. Therefor it is not possible to build this tool you want to have.

BTW: For what reason do you want it?

v-patcafAuthor Commented:
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v-patcafAuthor Commented:
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Let me know if you find one!
If you're using DHCP, you can look it up in the active leases - double click on the ip number.

Failing that from the command line type:

ping   (Or whatever number you're intersted in)

This will fore an ARP resolution
and then use

arp -a   (Or the adress you want)

To display the ARP table

This could easily be turned into a script
or even a GUI tool - Mail me if you would like me to write you one.
v-patcafAuthor Commented:
I understand this answer, but it requires that the ip address be known ahead of time.  I want to be able to find the ip address using the MAC address only
OK, I read the question around the wrong way.

Are you looking for a RARP server, which is basically supplies an IP number from a MAC->IP number table set up manually, or are
you looking for a diagnostic tool to determine the IP number of a known ethernet card.

If it's the second case, then I could write you a script along the lines of the example I gave you before, simply by forcing resolution of a range of IP numbers, and then looking at the ARP table to see which one matches the MAC address.
Just 'ping' the network broadcast address (xxx.xxx.xxx.255 on a class C net), then type "arp -a". This will give you a list of all the IP addresses that responded, along with their MAC address.

You could redirect this to a file and use an editor to sort, search, etc. I do this all the time when someone assigns a duplicate IP address to a system on my net.
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