find unknown ip address

if its in your arp chache you can find it by typing "arp -a"

clarification of the previous post, go in to cmd and type arp -a.

I have tried that... I have tried putting a static entry into my arp table to an IP and that didn't work either...

what type of device is it?

Its a 3c17700 Super stack switch....

3com

shouldnt you have a console port on that one where you can configure it by telnet?

http://support.3com.com/software/3com_network_supervisor_v4_0_1.exe
also found that one on 3com's site. might be usefull for mapping it up?
other than that I think I'm out of ideas im afraid.

I find myself getting new contracts all the time were the customer doesn't have IP addresses for equipment that has been shelved.

Yes there is a console port. I do not have a computer with a serial port at the moment.. There are alot of times were I have to configure equipment that I do not have the IP address for. I find my self resetting equipment all the time. I would try arp interogation however it takes a long time for class A addressing... I am hoping someone has a really cool trick to share with us...

The default IP address for 3Com switches is 169.254.100.101

Connect a patch cable to the switch and set your pc adress to 169.254.100.102 and you should be set. Unless someone has already changed the IP address on the switch.

One "undocumented" tip. If you don't have access to the passwords and errata, use these codes and perform a factory reset :

However I seriously recommend a null modem cable if you have to deal with issues like this on a regular basis. You can pick up on that connects to your USB port these days ;)

Cheers.

Adding to above, once you have set the IP on your computer, you can use IE / Firefox / ... to connect to the switch. I know its obvious, but :D

If there is a router in your network, then it becomes easy to find its IP
for cisco router, use "show arp" - it will give you a listing of the MAC addresses and their corresponding IPs.  \

and from a DOS
assuming your subnet was 192.168.1.0 with a subnet of 255.255.255.0
do

ping 192.168.1.255

then

type "arp -a"

Connect the device to  HUB.  In the same hub connect anther machine running wireshark/linux

Catch the traffic in promiscuos mode. you will get an MAC address to IP match easily.

Else , if you log into the switch/router , the switch port this device is connected should be of help.  

Worked amazingly.