If you are a network administrator or windows administrator you definitely from time to time need to find all IP addresses in the network subnet that open/used either to do some quick troubleshooting or setup new/edit existing network configuration. There are number of ways to find network addresses that are open/used and you can use tips provided in this article to do quick checking or use number of free applications/network tools to do it for you.
Steps to Find Out Your Network IP and Subnet Mask
First and foremost, you need to find subnet address and also check your network IP. Following shows you how to check Network IP and find out subnet address
1. Go To Start > Run > CMD
2. Type in IPConfig /all
3. Look for following information: IP Address, Subnet Mask
Usually, if you inside the network, you will get private IP address similar to 192.168.1.xxx, your IP address might be different. The subnet mask is important thing to note here. It is usually in form on 255.255.255.0 which means your computer can look at entire subnet of 255 adddresses. Bigger networks might have different settings such as 255.255.0.0 or different subnet settings. Note down the information.
Once you find out your individual network IP address, we can get IP addresses on network which are already in usage by using command line technique listed below:
1. Go To Start > Run > CMD
2. Type in following command:FOR /L %i IN (1,1,254) DO ping -n 1 192.168.1.%i | FIND /i “Reply”>>C:IPAddresses.txt
1,1,254 -The starting number and increment number and the last IP number, so it will start at 1 and increment by 1 every loop till it hits 254. You can change it to check only limited number of IP address, for eg. if you change it 2,1,4, it will only check 192.168.1.2, 192.168.1.3 and 192.168.1.4
-n 1 – Number of echo requests to send for pings
192.168.1.%i – This needs to change to match your network IP address, meaning if your network IP is 192.168.100.xxx then change it to 192.168.100.%i
C:IPAddresses.txt – Consider this a log file where results would be store, you can change to be saved where you like and name it whatever you like.
3. Press Enter and wait for it to Finish
4. Once finished, open up the text file IPAddresses.txt located on C Drive to see which IP addresses are used as this command will only output the responses from live IP addresses.
The above method does not require you install or download any network tool and works well without needing access to anything else. Its by far the easiest way to do quick LAN IP check before assigning static IP addresses to devices/computers/printers as it gives you network IP address list of which IPs are being used at that current moment.
Using Network Tools (AngryIPScanner)
You can on the other use IP scanners to scan networks and get more info in GUI based form if you prefer GUI over command line. I use Angry IP Scanner to do GUI based IP scanning as it provides good amount of information, has great features and is fairly light weight application.
You can download Angry IP Scanner directly from the source - http://www.angryziber.com/ipscan/ipscan.exe
On their website it says, it only works with 2000, 2003 and XP but I have tested it in Windows 7 environment without any troubles. They have new beta out that works with Windows 7 and Vista according to their website which can be downloaded directly from http://www.angryip.org/w/Download
After the download, open the Exe and put in the IP address range you want to scan and hit run. It will run through the list and give you results of scanned active IP addresses. Additionally, you can also check for open ports with this application (this will increase you scan time tremendously depending on how many ports you are scanning per IP). You can play around with features and see what information you need and add it to the viewing list. For more info on how the scanner works and the features visit: http://www.angryip.org/w/Documentation
Hope you find this article useful. Do leave us a comment if you have more easier ways to scan IP addresses in the network.