Network Traffic Analysis Made Easy Using Wireshark [2025 Guide]

 Wireshark Basics for security and analysis.  

Wireshark is a powerful and widely-used network protocol analyzer that captures and displays data packets flowing through a network in real time. It allows cybersecurity professionals, system administrators, and developers to see what's happening at a micro level in their network. Originally developed as Ethereal, Wireshark supports hundreds of protocols and runs on Windows, macOS, and Linux.

Its graphical interface makes it user-friendly, while also offering advanced features for filtering, coloring, and reconstructing TCP sessions. Wireshark captures raw packet data from network interfaces, which can then be analyzed for troubleshooting, performance tuning, or detecting malicious activity.

What sets Wireshark apart is its deep packet inspection—it decodes protocol layers, giving insight into everything from HTTP headers to SSL handshakes. Whether you're monitoring DNS traffic, investigating suspicious packets, or debugging software behavior, Wireshark provides unparalleled visibility.

It’s often used in both offensive and defensive security, making it a staple in ethical hacking and network forensics. However, Wireshark is passive—it doesn’t alter the data, only observes, making it safe and legal when used responsibly.

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🛠️ Wireshark Uses and working procedures. 

Wireshark’s most common use is for network troubleshooting. For example, if a website is loading slowly, admins can capture traffic to see where delays are occurring—maybe it's DNS resolution, maybe a server timeout. Wireshark makes it easy to pinpoint issues.

Another key use is security analysis. It can detect suspicious patterns like repeated login attempts (brute force), ARP spoofing attacks, or strange outbound connections to unknown IPs—often a sign of malware or backdoors.

In penetration testing, ethical hackers use Wireshark to monitor traffic after exploitation. Let’s say they’ve compromised a machine—they can watch what data is being sent or received.

For education, Wireshark helps students understand how protocols like HTTP, TCP, or FTP work under the hood. Watching the actual packet exchanges builds foundational knowledge.

It’s also useful in VoIP analysis, protocol development, and regulatory compliance auditing. Security teams can even use it to reconstruct conversations or file transfers if packets were captured properly.

 

1. Diagnosing Slow Network Performance

How to see in wireshark:

• Open Wireshark and capture traffic during the slow performance.
• Apply filter: tcp.analysis.retransmission
• Look for retransmissions, duplicate ACKs, and high latency.
• Use "Statistics > TCP Stream Graphs > Round Trip Time" to visualize delay.
• Analyze slow server responses by following the stream (Right-click > Follow > TCP Stream).

🔐 2. Detecting Suspicious Traffic (Malware/Data Leak)

How to see detection of malware in wireshark

• Capture traffic over time or from the suspicious host.
• Use filter: ip.dst != your_internal_IP_range or look for tcp.port == 443 to inspect encrypted data.
• Go to "Statistics > Endpoints" or "Conversations" – sort by bytes sent.
• Flag unknown domains/IPs; check for odd protocols or large outbound traffic.
• Optional: Export the session and scan with tools like VirusTotal.

🛡️ 3. Identifying ARP Spoofing Attack

How to identify ARP spoofing in wireshark

• Use filter: arp
• Look for multiple ARP replies for the same IP address with different MACs.
• Go to "Statistics > Protocol Hierarchy" and check ARP packet volume.
• Use the "Duplicate IP addresses" detection script or manually inspect if two devices claim to be the router.

 4. Troubleshooting VoIP Call Drops

• Apply filter: sip || rtp
• Analyze SIP handshakes (INVITE, ACK, BYE) to confirm call setup/drop.
• Go to "Telephony > RTP > RTP Streams" to inspect jitter and packet loss.
• Select a stream and choose "Analyze" to check latency issues.
• Use "Statistics > VoIP Calls" to list call logs.

🌐 5. Inspecting HTTPS Handshake Failures

• Filter: ssl.handshake or tls.handshake
• Look for Client Hello and Server Hello messages.
• Check for TLS version mismatches, cipher suite errors, or missing Certificate response.
• Use "Follow TLS Stream" for more insight (note: may not decrypt).
• Confirm cert expiry or SNI mismatch using certificate fields.