Wireshark is used by network professionals to diagnose issues like dropped packets and optimize network performance while identifying any security threats.
The tool provides 20 default color-coding rules to identify various packet types and also displays the network interface through which packet capture occurs.
What is Wireshark?
Wireshark is a free packet analyzer designed to aid network professionals in diagnosing and troubleshooting network problems. It features protocol dissection, data filtering and visual data visualization – as well as live traffic capture/analysis/pre-recorded packet analysis/live traffic capture/analysis capabilities as well as various network types such as Ethernet, USB token rings etc – it even uses promiscuous mode or port mirroring so more data than would normally be accessible would be monitored simultaneously by one switch!
The tool offers an intuitive user experience, making it simple to learn. Its three panels display information on captured frames; its top panel lists each frame individually with key data displayed, while its middle panel shows packet details to help identify whether a frame belongs to a network layer, data link layer or transport layer. Finally, its bottom pane presents raw frames showing their hexadecimal rendition on one side and ASCII values on the other side of its display window.
Users need to understand all five OSI layers when trying to interpret a frame, since problems may originate in one layer or another depending on its nature; for instance, issues while browsing online could point towards problems at layer 3 (network layer).
Wireshark provides another useful feature by color coding packets based on specific criteria, making it easier to differentiate the various types of packets and identify what source they belong to and who it communicates with. UDP packets are marked in light blue while ICMP ones stand out with light pink highlights; errors within a packet are represented with black highlights.
The application can also perform several other functions, such as reading MAC addresses and displaying current connection statuses, making it particularly helpful in analyzing unicast traffic such as VoIP calls. Furthermore, this software may even provide geographical data based on MAC address – however this information may not always be reliable as IPv4 addresses may be falsified.
Wireshark stands out as a portable application capable of running on multiple operating systems. Additionally, it can open files containing packet data captured using tcpdump or WinDump and export some or all of them in various formats.
Installing Wireshark
Wireshark can be installed in various ways, one being downloading it directly from its official website and then running its installer to install it on your system. Once downloaded, run its installer to complete installation; once complete it will ask you to review its license agreement before asking if you want shortcuts created and once all options have been selected it will start installing itself and once complete you can begin using Wireshark to capture and analyze network packets.
Wireshark requires that users possess an in-depth knowledge of networking concepts such as TCP/IP, DNS and HTTP in order to interpret its results and address problems efficiently. Furthermore, filter usage will allow them to display specific traffic while decreasing how much information must be processed at once.
Wireshark can be downloaded directly from either Ubuntu Software Center or a personal package archive (PPA). After installation, add its repository by opening up terminal and inputting this command:
Once this step has been completed, a series of commands must be executed to compile and build the software from source. This may take some time as it requires copying over source code before compiling into binary form – once complete you will be able to launch Wireshark from its final destination directory in /usr/bin/wireshark.
If you installed Wireshark through a PPA, it is wise to unsubscribe after installation is complete in order to limit exposure to malicious code from this source. To do this, open up a terminal window and enter this command:
If you have an older version of Ubuntu, Flatpak packages provide a quick way to install Wireshark. First ensure your system has installed Flatpak runtime before following these instructions to install:
Capturing Packets
Wireshark can help network administrators capture network packets for analysis when network troubleshooting becomes necessary. Packet capturing, also known as sniffing, involves recording the network traffic that passes between your computer and others on the Internet. To capture all unicast traffic that’s not directly addressed to your machine. Promiscuous mode allows Wireshark to see all this traffic easily.
Starting a packet capture is easy! Clicking the shark fin icon or pressing Ctrl+E will launch a program to capture real-time data packets, with an increasing progress bar to show as it begins grabbing them in real-time. When your capture has completed, press the red stop button on the toolbar to stop taking more data packets.
Wireshark stands out from commercial network monitoring tools by having the unique capability of capturing encrypted traffic – an invaluable feature when troubleshooting security issues or investigating network attacks. Once captured, network traffic can be viewed either online or offline.
Wireshark can show not only network packets but also information regarding OSI model layers and protocols – this information will allow you to gain a better understanding of what’s going on within your network and why certain issues have surfaced.
Color coding and other visual cues help distinguish different types of traffic, but Wireshark presents an overwhelming amount of data for you to sort through. To make things simpler, filters can help narrow down what packets Wireshark grabs; capture filters restrict what Wireshark actually grabs while display filters limit what appears on-screen.
Once a packet is selected, its details pane displays information in collapsible form. You can use right-click to perform various actions on that packet such as marking it for marking purposes or applying filters based on protocol type streams of data.
While you can capture as many packets as desired, keep in mind that the more packets you gather will result in a larger capture file. For optimal results, limit captures to no more than 100 megabytes for optimal results. You can save captured packets for later by using File > Save As or export option.
Analyzing Packets
Wireshark makes packet captures easier to read with its intuitive packet list pane that organizes data by protocol and provides easy navigation through it all. Each packet in this list is clearly labeled, making it simple to locate specific ones within a capture. Clicking any packet opens up its detailed packet view and byte view windows – ideal if troubleshooting issues with browsers like YouTube where three-way handshake issues might be the source. Using TCP options within Wireshark could quickly resolve them swiftly!
Wireshark can also help identify which version of TLS (transport layer security) an application is using, which is helpful if you’re trying to verify whether applications are correctly using this encryption protocol, or detect whether someone has exploited any loopholes in its implementation. It can also identify versions of SSL being used by specific websites.
Wireshark can help not only to troubleshoot specific protocols but also understand how different network devices operate and monitor security systems effectively. It can verify if firewalls, intrusion detection systems and intrusion prevention systems are blocking attacks while alerting administrators of their presence on the network; furthermore it can examine malware communications patterns to assist analysts with creating effective countermeasures against advanced persistent threats (APT).
Wireshark can not only offer a visual overview of network traffic, but it can also assist software development and testing by testing how new network protocols perform in real-world situations, helping developers understand older networks’ design features, diagnosing bandwidth issues by showing which apps are using up the most resources on the network, or diagnosing bandwidth shortage issues by showing which applications are taking over the entire bandwidth.
Gerald Combs initially created Wireshark (then known as Ethereal) in 1998 as commercial packet analyzers were either too costly or did not support Solaris and Linux servers used by CACE Technologies at that time. After CACE was acquired by Riverbed Technologies, their acquisition absorbed Ethereal into their corporate legacy funding plans as a volunteer project and ensured its continuation.
