Wireshark Advanced: A Complete Guide to Captures and Analysis

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If you're already familiar with Wireshark and want to take it a step further, this article is for you. We'll explore how to truly leverage its capabilities, from basic captures to advanced traffic analysis , including filters, colors, protocols, and practical applications in cybersecurity analysis , performance optimization, and troubleshooting.

Throughout this text, you'll find many concepts explained calmly and in simple, everyday Spanish—concepts commonly found in professional tools, courses, books, and labs like TryHackMe—but applied to a practical context. The goal is that, by the time you finish reading, you'll be able to navigate the Wireshark interface with ease, capture what you need , and understand what's happening on your network.

What is Wireshark and why is it so important?

Wireshark is essentially a network protocol analyzer (a classic packet sniffer) that allows you to view, one by one, the packets entering and leaving your network interfaces, whether they are public Wi-Fi networks , Ethernet, or others. Each packet is captured, isolated, and displayed in real time, with all its details.

We're talking about a free and open-source program , distributed under the GNU General Public License v2. This means there are no cut-down versions or "demo editions": what you download is the full version, with all the features, and any developer can review its code to ensure it doesn't do anything suspicious.

The project is managed by the Wireshark Foundation , a non-profit organization that coordinates the development, documentation, and distribution of the software. Many companies and professionals who rely on Wireshark for their work contribute donations, which keeps the tool alive and allows it to continue evolving.

Wireshark is available for Windows, macOS, and Linux distributions like Ubuntu , and can be downloaded from its official website, wireshark.org. Once installed, you'll see an interface that might initially seem overwhelming: hundreds of lines changing rapidly, columns with IP addresses, protocols, lengths, timestamps… but all of that is pure gold for diagnosing faults, detecting attacks, or understanding what your devices are doing.

Wireshark interface: panels, preferences, and getting started

When you open Wireshark, the screen is organized into several main panels: the package list, the details of the selected package , and the raw view (hexadecimal and ASCII bytes). Understanding these panels is essential for working effectively.

The top panel displays all captured packets. Each line corresponds to a packet and includes information such as packet number, time, source IP address, destination IP address, protocol, and a brief summary. The middle panel shows the packet's layer breakdown (link, network, transport, application), and the bottom panel displays the bytes in hexadecimal format and their text representation.

From the settings menu, you can open Wireshark's preferences and adjust things like the time format, how the panels are displayed, the language of the fields, or even hide certain elements. For example, you can change the panel layout or disable the display of HEX bytes if you prefer to focus only on logical analysis.

Navigation within a capture is also key: you can go directly to a specific packet number, jump to the first or last in the list, and move through conversations using keyboard shortcuts. Furthermore, you can bookmark packets to return to them later , which is very useful when following a long flow and need to remember certain key points.

Traffic capture: interfaces, limits, and packet types

Before analyzing, you need to capture. Wireshark lets you choose which network interface you want to listen on : the Ethernet card, Wi-Fi, virtual interfaces, tunnels, etc. Not all interfaces support the same level of detail, but generally you'll be able to see the traffic crossing your device and even, in certain modes, the traffic circulating on your local network.

For practice, it's very common to work with limited captures. You can, for example, start a capture limited to 1.000 packets , or configure it to stop automatically after 5 seconds. This is useful for avoiding huge files and focusing on specific time windows of activity.

Wireshark also supports capture filters, allowing you to record only certain packets from the start. A typical example is capturing only UDP or TCP traffic . For instance, you can start a capture that only captures UDP packets if you're interested in online games or streaming services, or limit the capture to TCP when you want to study HTTP, TLS, FTP, etc. sessions.

Once you have what you need, you can save the result to a file with the .pcap or .pcapng extension, for example as “example_tcp.pcap” , and close Wireshark. Then you can reopen the program, load the file, and analyze it at your leisure, without the traffic continuing to move in real time and without risk of losing anything.

Working with time: marks, differences, and temporal analysis

The time field is one of the most powerful in Wireshark. In the packet list, you can see when each packet was captured, but you can also measure how much time has passed between the start of the capture and a specific packet , or between two specific packets. For example, you can look at the time it takes to reach packet 300 to see how a communication evolves.

A very practical feature is the ability to set a packet as a zero-time reference . This allows you to redefine time "0" at any point in the capture, so that all other times are measured relative to that packet. This is ideal when you want to study a specific exchange rather than the entire session.

By combining timestamps with filters and flow tracing (follow TCP stream, follow UDP stream), you can fairly accurately see the latency, delays, forwarding, and retransmissions occurring on the network. This is especially useful for diagnosing lag, bottlenecks, or packet loss.

Layered analysis: from the MAC to the application

One of Wireshark's greatest strengths is that it lets you see each packet broken down by layers of the OSI or TCP/IP model. Starting from the bottom, you can see what physical medium or link type is being used (for example, Ethernet) and the type of interface that supports it.

At Layer 2 (data link), you can check which protocol is being used , typically Ethernet II in modern networks. This is where the "EtherType" field becomes important, as it may display values ​​such as 0x0800 (indicating IPv4) or other less common identifiers. You can search for packets with a specific value, such as 0x0800 or 0xEBF2, using filters or searches within the capture.

Moving up to Layer 3, you'll find the network protocol, usually IPv4 or IPv6 . Here, the source and destination IP addresses are displayed, and you can expand the field tree to see other details such as TTL, fragmentation, options, and so on. Identifying the source and destination IPs is one of the most basic, yet most frequent, tasks when troubleshooting.

At layer 4, Wireshark tells you whether you're dealing with TCP, UDP, or other transport protocols . This is where you see the source and destination ports, TCP flags (SYN, ACK, FIN, RST), sequence and acknowledgment numbers, and key details for understanding if a connection is stable, if there are retransmissions, if packets are being lost, or if it has been abruptly closed.

Finally, at the application layer, Wireshark attempts to interpret the content based on the detected protocol: HTTP, HTTPS (TLS/SSL), DNS, DHCP, FTP, RTP, SIP, and many others. When traffic is not encrypted, it's even possible to see the content in plain text, including HTTP headers, FTP commands, and even credentials if they are being sent insecurely.

Searches, filters, and text strings within packages

Working with large captures requires the use of powerful filters and search capabilities. At the top of Wireshark, you have the display filter bar , which allows you to show only the packets that meet certain conditions: for example, `ip.addr == 192.168.1.50` to focus on a specific device, or `http` to see only web traffic.

If you suspect that passwords or sensitive data are being transmitted unencrypted in a captured packet, you can search for text strings within the packet content. You can check if any packets contain, for example, the word "pass" or "content" in the captured data. You can also check if these strings appear in the packet's summary or information, not just in the body.

This is especially useful when analyzing insecure protocols like HTTP or FTP. In training environments like TryHackMe, one of the typical tasks is to extract credentials sent in plain text through these services, or to detect forms that send unencrypted information, which represents an obvious security risk.

Beyond text strings, you can use much finer filters by combining protocol fields, logical operators, and comparisons. This allows you, for example, to isolate only failed DNS requests, TCP packets with errors, or messages from a specific RTP stream.

Colors and highlighting rules for better traffic visibility

Wireshark includes a color-coded system for packets that helps you quickly distinguish different types of traffic. Green is typically associated with "normal" TCP traffic, blue with UDP or DNS traffic, and black or red indicates errors or anomalies. Just by looking at the screen, you can tell if everything is working reasonably well or if there are too many problematic lines.

From the settings menu, you can enable or disable the color-coded view. If needed, you can also modify the background color of specific rules ; for example, create a rule that highlights all TCP sessions in a particular shade, or that marks retransmissions or malformed packets in a different color.

In addition to changing colors, you have the option to disable a specific rule without deleting it, so it stops coloring packages but you can reactivate it later. This is very useful when you're testing different schemes and don't want to lose your existing settings.

Another interesting technique is to color-code all the packets belonging to the same TCP or UDP conversation . This way, you can visually follow the entire flow between two endpoints, even when it's mixed with hundreds of other parallel connections. You can then navigate through these highlighted packets much more easily.

Diagnosing network problems at home and in the company

Although Wireshark is a professional-grade tool, it can also help home users understand what's happening with their connection. For example, if you experience lag or Wi-Fi interference while gaming online , you can analyze the traffic to see if packets are being lost, arriving out of order , or experiencing excessive delays along certain parts of the connection.

In this context, it's common to focus on UDP traffic, which is used by many games and real-time applications. If, when filtering by UDP, you see many lines marked with error colors, out-of-order packets, or retransmissions, you'll know that the problem isn't just a high ping in a test, but something deeper related to route stability or the saturation of a node.

Wireshark is also very useful when a webpage won't load, a printer disappears from the network , or an internal service fails. With the capture in front of you, you can see exactly where the communication breaks down: whether the request leaves your computer but never receives a response, if there are DNS errors, if the server responds with an error code, and so on.

From a privacy standpoint, this tool lets you see what data your devices send over the internet. It can detect if a device is "talking too much" to the cloud, maintaining connections to unknown servers, or sending unencrypted information. All of this helps you audit the behavior of IoT devices , mobile phones, IP cameras, smart TVs, and any other connected gadget.

In home networks with many devices, you can isolate the IP address of each device and observe which servers it connects to, how often, and what type of content it transmits. This way, you better understand your network's raw traffic and can make decisions such as segmenting devices, blocking domains, or changing configurations.

Advanced analysis: HTTP, DNS, network scans and attacks

In more advanced environments, Wireshark becomes a key ally for security analysis and incident investigation. It allows for detailed study of HTTP traffic, DNS queries and responses, port scans with Nmap , ARP poisoning attempts, SSH tunnels, and much more.

With HTTP, you can review headers, response codes, requested URLs, and, when there's no encryption, even the content of forms or files. With DNS, you'll see which domains are being resolved, which servers are being queried, and whether there are any suspicious responses or domains that don't match the normal usage of the equipment.

Nmap scans leave characteristic patterns on the network: multiple connection attempts to many ports, use of specific TCP flags, etc. With the appropriate filters, you can detect these activities and confirm if someone is mapping exposed services on your infrastructure.

ARP spoofing/poisoning can also be detected by observing how IP and MAC address associations are modified on the local network. And with SSH tunnels, even though the content is encrypted, you can still analyze connection patterns, session duration, and the volume of data transferred.

Many of these exercises are part of hands-on labs like those at TryHackMe, which focus on analyzing malicious or suspicious traffic . You'll work with pre-generated captures to learn how to recognize indicators of compromise, attack vectors, and anomalous behavior using only Wireshark.

Wireshark 4.6.0 on macOS: pktap metadata and process analysis

One of the most interesting improvements for Mac users comes with Wireshark version 4.6.0 , which introduces native support for macOS pktap metadata. This allows you to associate each network packet with the system process that generated it, offering a powerful level of detail.

Thanks to this integration, Wireshark can display information such as the PID (process ID) and the name of the application originating the traffic, along with other relevant metadata. This greatly simplifies application debugging, as you know exactly which component is opening connections, consuming bandwidth, or causing errors.

The metadata also includes data on flow identifiers and dropped packet statistics, enabling a more detailed analysis of performance issues. This information is typically captured using tcpdump with the -ky and -K options , and then imported into Wireshark, which interprets and displays these blocks in pcap-ng format.

For development and security teams in the Apple ecosystem, this represents a significant leap: they can investigate incidents with very precise attribution to specific processes, detect anomalous behavior within their own apps, and validate that security and privacy policies are actually being followed.

Furthermore, the Wireshark 4.6.0 installer for macOS is universal for Arm64 and Intel architectures , thus simplifying installation on modern Macs with Apple Silicon and on slightly older computers with Intel processors.

Wireshark as a professional tool: courses, books and modern environments

Advanced use of Wireshark is a recurring topic in specialized training courses, which showcase its most powerful features for debugging, auditing, and security tasks. These courses teach how to configure the tool from scratch , customize it, and analyze the most common network protocols in corporate environments.

A significant amount of time is typically dedicated to protocols such as HTTP, FTP, SSL/TLS, DNS, DHCP, RTP, SIP , and others commonly used in Voice over IP, web services, and encrypted communications. Practical case studies are conducted to diagnose slow speeds, call quality issues, service outages, and misconfigurations.

In parallel, advanced books and resources have emerged, focused on network professionals, cybersecurity specialists, and students who want to master Wireshark in modern scenarios. These materials typically combine TCP/IP theory, TLS, packet analysis, and advanced filters with practical exercises and guided labs.

A common approach is to integrate Wireshark with other security and monitoring tools, such as Snort, Suricata, Zeek, or the ELK stack (Elasticsearch, Logstash, Kibana), within SIEM platforms. The idea is to use Wireshark for low-level, detailed inspection, while the other tools provide correlation, alerts, and high-level dashboards.

It also covers specific applications in IoT networks and systems using artificial intelligence, where traffic visibility is crucial for detecting vulnerabilities, misconfigured devices, or unexpected communications. Mastering Wireshark in these environments makes the tool a strategic resource for the security and optimization of complex networks.

Overall, Wireshark goes from being a simple sniffer to becoming a fundamental tool in advanced monitoring, fault diagnosis, threat analysis, and deep understanding of how applications and services behave on the network.

With everything it offers, from basic capture and filtering functions to advanced capabilities for analyzing by protocol, colors, times, and process metadata, it's clear that Wireshark is an essential tool for anyone who needs to understand what's really happening on their network, whether at home, in a small business, or in a large organization.