How can I find all valid IP addresses on a LAN?

Question

I'm trying to get a computer to list out all of the valid IP addresses that it thinks it can talk to in a local area network, basically to "ping everything, and tell me what answered". I need to do this with both Windows and Linux machines. Is there a cheap and dirty utility that can scan these and report back?

I also have a VPN setup, and would like to be able to do the same thing over the VPN. Is that possible?

Thanks!

PS this is for honest reasons! it's my own LAN and VPN; it's just a bit more complex than I can get my head round sometimes and I need something to map out what's finding what and what isn't. Cheers!

Answer 1

Hi wild_eep, actually ipconfig will NOT do this for you, but this is still easy to do with what you have right now, no need for any special programs or utilities. All you need to do is run a script at the command line, this is the quick and dirty method like you said.

Let's start with windows: Go to Start, Run and type "cmd" to bring up a command window. Give this command (without the quotes):

"FOR /L %X IN (1,1,254) DO PING 192.168.1.%X -n 1"
and give it a few minutes to complete.

Substitute the 192.168.1 above with whatever your own subnet is. If you have multiple subnets, then run around to a machine on each subnet and repeat this.

If you have many subnets, this might get cumbersome, but there are many programs out there that will help you, like wsping pro for example, some are free, some are not. Just try Googling for "free network monitoring tools".

Also note that this will ONLY give you the list of machines that are currently powered up, connected and able to respond to a ping... it'll miss machines that are powered off, or might have software firewalls that will reject a ping request.

Also, for the Unix version, it's probably easiest to run this same type of command from a short shell script. For example, here is a Bourne shell script that will do it:

#!/bin/sh
X=1
while :
do
ping 192.168.1.$X 2
X=`expr $X + 1`
if [ $X -eq 254 ]
then
exit 0
fi
done

Write that in a text editor, save it as mypingscan.sh and make sure it's an executable file (using chmod 755 mypingscan.sh) and run it. You can easily adapt this one to ping multiple subnets, just use a $X for the subnet and a $Y for the host.

Hope this helps, good luck.

Answer 2

Snag a copy of Languard Network Security Scanner at http://www.gfi.com/languard/

It's a timed trial version. Once the trial period expires, it runs with reduced functionality but you'll always be able to do a ping sweep of a class C network.

As long as the target network is reachable, it will work. This includes VPNs.

Answer 3

Hello,

there is small untility naming "Net Scan" from Soft Perfect inc, through this you can find IP's of each PC, computer name of PC's availble on LAN & all the shared resouces associated with these PC's.

Another small software is Ethereal, which is good Ethernet scanner, it may also help you.

Answer 4

I use angry IP scanner, you simpl put in the start & end IP then it pings everything inbetween & tells you if ti's alive or dead - it can also report back mac address etc etc & has port scanning capability as well.

worto.

Answer 5

The best one i've used can be found here -
http://www.angryziber.com/ipscan/
I've used it in Windows and it is very good. It gives you details of the IP, Domain, Host name and Mac address.
The site also tells you how you can use it in Linux.

Answer 6

You have two options to reach the place where you can write a command to give you the information you want.That is to enter the "command prompt".
1.Click start and then run,there type cmd.or
2.Click start,point to all programs,accessories then click command prompt.
Now on the command prompt type ipconfig/all and then press Enter.
This will give all the information you've asked.

Answer 7

goto start and run. type cmd and then enter
then type ipconfig /all and ennter

this will bring ya whole ip config up for ya sys/ or failing that go to ya adrees bar clear and put the following.whats my ip

Answer 8

valid: 10.0.0.0 - 10.255.255.255 172.sixteen.0.0 - 172.31.255.255 192.168.0.0 - 192.168.255.255 192.0.0.one million could be any valid cyber web addresses given to you by using your ISP Make your question greater precise

Answer 9

I Think you need to ask this on a hacking site, not answers.

Answer 10

there r a lot of softwares for this. i suggest you superscan and
blue port scanner.

to download visit www.chackdephattey.com