How to know of a device's IP ?

Question

Let's just say I have a new manageable device, such as a router or even a manageable switch (Layer 2/3). All these device would have an IP address where you can launch your browser and key in that IP address and access it. However, what if, for some reason, the IP address of the device has been forgotten. Is there any "IP Sniffer" software out there that can scan for devices that si directly connected to my computer's LAN port?

If I wanna find out the IP address of the router or switch, I would have a direct connection between my computer and the device so that the software can scan for any immediate attached devices.

I would not want to factory reset that device as that would make me lose all my settings.

Thanks in advance for your help.

Answer 1

isolate the device interface and a pc with ethereal on the same switch - run ethereal with no filters, reboot the device in question and wait for it to spit something out. scanning for the address means that you need to know the network/subnet that the address is on, but if you just listen promiscously then you will eventually see something come out of the device, especially if it's a router, but even a layer 2 switch will spit something out.



or just use "tcpdump" if you have a linux box.

Answer 2

I usually face this kind of problem regularly, as I tend to forget the IP's of my managagable decives in unmanagable numbers.



For that I suggest you install a free network scanner by the name nmap

http://www.insecure.org/nmap/



Download it and install it

You must have a vague idea of atleast the subnet of the device. Set the IP of your machine to some IP of which you are sure is not assigned to the device.



Then isolate your own machine and the device in a subnet or shutdown all other computers/ devices.

Deactivate your firewall.



The in a command window type this

nmap -sP 192.168.1.1-254



If the subnet is 192.168.1.0/24



this will scan the whole shubnet and list IP addresses that respond. Hope your device's IP is listed.



If not try other types of scans with nmap.

If all else fails, try ethereal network sniffer, and leave it running, maybe the device will send some IP data giving you some hint of it.



Regarding, if the device can only be managed from a specific IP, that is a little tought, as you have to do a number of permutations and combinations to find the actual management IP, and the method can very from situation to situation. Maybe some shell scripting skills can help.



BTW I prefer GNU/ Linux for such types of jobs.

Answer 3

you say you have an "New Managable Device" but you don't want to reset the factory settings, HMMMMMMMM makes me wonder.



okay, you manual should have the IP address. If not contact the manufacture of the device, and they can usally provide the address. however if you have changed the address. then you could be SOL. and just may have to reset the factory settings. so sad really

Answer 4

you're on the right track here. doing an ipconfig on the dos prompt (considering it is a windows computer) should give you a default gateway number - that's the ip of the router.

details:

for Windows 2000/XP --> start, run, cmd, ipconfig

for Windodws 98/SE/ME --> start, run, winipcfg

Answer 5

on the Local Area Network look Internet Protocol (TCP/IP), click properties, then check obtain IP Address Automatically

Answer 6

on the computer were the device is installed, click start> accessories>command prompt



Then type "ipconfig /al"

Answer 7

what is this secret "device"?

Answer 8

ipconfig/all

Answer 9

http://www.softperfect.com/products/networkscanner/



here you go