Network administrators can perform better if they have relevant information at their fingertips. There are certain tools that help network admins to capture and analyze network data so that they could figure out what is going on. Wireshark Network Analyzer is one such free tool and this review of Wireshark, in plain language, tells you what all it offers.
Wireshark is based on WinPcap as it requires the latter to be installed on your computer. If it is not already installed, Wireshark prompts and installs it for you. Certain other tools that I’ve used – like URL Snooper – too employ WinPcap to sniff on packets traveling through the network.
What is WinPcap
WinPcap is always installed as a separate program. It is a tool to capture network packets without the interference of any protocols. It includes kernel level packet filtering, network statistics engine and a driver. With the help of this driver, it bypasses all network protocols and accesses the low level network layers.
For your information, TCP/IP or ISO OSI etc. models used in a network scenario, for data communication, have different set of layers. We generally work at the application level and it is the topmost level in both protocols – TCP and OSI. Here is an image to make it clear. It shows layers in both OSI and TCP. WinPcap operates at network level — bypassing all other upper layers
To access the low level layers, WinPcap bypasses these and other layers and digs out data packets moving in the lower network level. Thus, it helps in providing information to different programs about outgoing and incoming data packets. This information is then used by different programs to dig out different information.
WinPCap is listed as a separate program in Add/Remove Programs or Programs and Features. If you remove WinPCap, applications dependent on it – like WireShark – will fail to perform.
Wireshark Network Analyzer
Wireshark is quite famous among network admins so I decided to check it out and see what it offers. As said above, it will prompt you to add WinPcap to your computer and will install it for you. When you open the program after installing Wireshark, you get a screen with different options divided into three columns. The options include:
1. Interface List: If you have more than one network adaptors, you will have to select which one(s) you wish to capture. For example, when you click on it, Wireshark shows you list of network adaptors on your computers – including the WiFi. You just have to select one or more of these network adaptors for Wireshark to determine the packets coming in and going out via these adaptors. The dialog box on my computer was like the image below. The virtual network adaptor of SpotFlux is also shown in the image. Yours may vary based on the network adaptors you have.
2. The second option is start packet capturing. When you click it, it will show data pertaining to the network card(s) you selected.
3. The third item in first row is to set up capture options. Here, you can again select the network card(s), place filters, give a name to capture file among other things.
The second column has a list of recently opened capture files and sample capture list.
The third column is related to documentation etc. Here is how the entire GUI looks like. To enlarge the image, click on it.
Once you captured data, you can save it under any name for later examination. If you forget to save and close the program, it prompts you to save the data and also gives you option to exit without saving.
Other features of Wireshark Network Analyzer
Among other features that caught my attention was the handy toolbar that has options to start, stop packet capturing. It also has options to set up preferences and to launch help. Other options are to restart packet capturing without saving the file, close the capture file, reload the capture file etc. In short, it offers you shortcuts to perform different options without having to navigate using the menu bar.
Color coding is yet another good feature of Wireshark Network Analyzer. You can use the ready-to-use color codes or you can set up custom color codes in Preferences on toolbar. The color coding helps you identify the type of data packets.
The bar just below the toolbar contains options to set up filters. I did not use this but it is easy access to filters for admins who wouldn’t want to open up the capture options dialog each time. You can directly type into the text box on the filter bar or you can click on Expressions and then create an expression using the available options. Setting up filters is just like you do when you are handling data in Excel so it should not be inconvenient.
In the capture window, when it is showing different data packets, you can right click on a data packet to see its details. The lower window shows details pertaining to that particular data packet.
In short, Wireshark has all the facilities to observe network data without sweating out. Its graphical user interface makes it easy to perform different tasks. If you are a network admin and wish to keep an eye on the data packets, Wireshark is for you.
Wireshark Network Analyzer free download
You can download from its official website.
Go here to check out some more Free Network Monitoring Tools.