Introduction: Map Your Network Visually.
This is a nice little graphical utility to graph out what and who might be on your network. Makes documentation much easier for those in charge of the network to assess networking assets. You can certainly use it for business, but I love using it for home also. We will be using jnetmap for linux. Impress a friend with it. There is a product that is java based and more platform independent with the same name,
Note this should map all normal ip devices, including MSWindown, OSX, and etc. This software requires knowledge of local area networking and Internet protocol basics. i.e. you should know what an ipaddress (equivalent of a phone number or house address for a computer) is and how it is used.
Step 1: Installation.
You need to download http://sourceforge.net/projects/jnetmap/files/jNetMap%200.5/jNetMap-0.5.deb/download from sourceforge.
From the command line go to where you downloaded it to and install it.
$ cd (download directory)
$ sudo dpkg -i jNetMap-0.5.deb
If your Debian based repository supports it:.
$ sudo apt-get install jnetmap
Go to the Applications menu > Internet > jNetMap to run it.
Step 2: Your First Network Map.
Once you have followed the instructions in the previous step, you should get the start up screen.
Since you probably have not done a map before, You will want to choose "Create a new map of your network".
Then you will want to go to the menu and go Tools > Network scanner.
That you give you a screen to choose you network. It defaults to 192.168.1.1. You need to make sure that is correct.
Either from the command line:
or go to your desktop and display Connection information.
Once you are sure that the network is right, press the scan button.
Step 3: Results?
After a while, you should get a listing of the ipaddresses being used on the network. Press add when it is done searching.
You should get a network map. You may have to use your mouse to arrange the connections.
If you click on one of the devices you should get additional information about that device at the right hand column.
You can even get port information by going to Tools > Port scanner. I did a port scan on a printer server (192.168.1.99)
Step 4: Other Possiblilities
You also have a feature to add other devices (real or planned) to the network map. You can even add information about the devices connected to your network. I have given you just enough to to get your feet wet. Have fun!
Step 5: Identifying the Maker of a Nic.
Identifying the maker of a nic (network interface card). This can be very important if you want to see what kind of equipment is connecting the the network. Every nic has a mac (media access control address) and usually the first several characters of that hexadecimal number usually indicate the the maker (vendor) of the equipment. If you use pretty much the same equipment on your network, a listing of the mac addresses being used will allow a rogue device to be spotted pretty easily. It is a good idea to keep a listing of all the mac addresses in use to compare against what is being used. Finding out what vendor a nic was made by makes it easier to find a rogue system. For example, at the school where I used to work we pretty much used 3com nics. Usually, if a student tried to hook up his or her computer to the network, they might have a Realtek based nic instead of a 3com. Those mac addresses will stick out like a sore thumb. going to the dhcp server to get a list of connected clients is the easiest way to see what is connected if jNetMap is not connected or you have no software to see what is on the network.
There are other tools to look at for getting information about your network. They usally require admin rights and or a bit more experience with netowrking. Here are just two:
nmap (with a gui front end such as zenmap)