How to Use TcpLogView to Monitor TCP Connections
TcpLogView is a lightweight Windows utility that logs TCP connections in real time. It captures local and remote IPs, ports, timestamps, process names (when available), and connection status changes, making it useful for troubleshooting network issues, auditing activity, or monitoring suspicious connections. This guide shows a practical, step-by-step workflow to install, configure, and use TcpLogView effectively.
1. Download and install
- Go to the official TcpLogView download page (NirSoft) and download the ZIP for your Windows architecture (32-bit or 64-bit).
- Extract the ZIP to a folder where you want to keep the tool. TcpLogView is portable — no installer required.
- If Windows blocks the executable, unblock it: right-click the EXE → Properties → check “Unblock” → OK.
2. Start TcpLogView and understand the interface
- Run TcpLogView.exe as administrator (right-click → Run as administrator) to ensure it can access all connection info.
- Main columns you’ll see:
- Date/Time: when the event occurred
- Local Address/Port and Remote Address/Port
- Process Name / PID: identifying the application (may be blank for system connections)
- State: connection state (e.g., ESTABLISHED, TIMEWAIT)
- Direction: outbound or inbound
3. Configure logging options
- Options → Advanced Options:
- Log only new connections — reduces noise by showing new establishment events.
- Include name of process that opened the connection — enables process mapping (requires admin).
- Resolve IP addresses to hostnames — useful for readability but can add latency.
- Options → Auto Refresh: set refresh interval (e.g., 1000 ms) to control update frequency.
4. Filter and sort to focus on relevant traffic
- Use the filter bar (Ctrl+L) to create quick filters:
- By IP: remoteip contains 203.0.113.5
- By port: remoteport = 443
- By process: process contains chrome.exe
- Click column headers to sort by timestamp, remote IP, or state to spot patterns (e.g., repeated connection attempts).
- Use View → Find (Ctrl+F) for one-off searches.
5. Save, export, and automate logging
- To save captured data: File → Save Selected Items or Save All Items. Supported formats: CSV, XML, HTML, tab-delimited.
- For periodic logging, run TcpLogView from the command line with parameters:
- Example:
Code
TcpLogView.exe /stab “tcp_log.csv”This saves current data to a CSV file. Combine with scheduled tasks to run at intervals.
- Example:
- To append continuously, run TcpLogView with /scomma and redirect output with scripts (use carefully to avoid data loss).
6. Practical use cases and examples
- Troubleshooting slow web access: filter remoteport = 443, then note which processes are making many TLS connections and their remote hosts.
- Detecting unwanted outbound connections: sort by remote address and look for unknown hosts or frequent short-lived connections (SYN/SYN-ACK/TIMEWAIT patterns).
- Auditing application behavior: run TcpLogView while launching an app to capture which servers it contacts and which ports it uses.
7. Tips for effective monitoring
- Run as admin to get process names and PIDs.
- Use hostname resolution selectively—enable only when needed.
- Combine TcpLogView logs with firewall or packet-capture tools (e.g., Wireshark) for deeper analysis.
- Keep refresh interval moderate (500–2000 ms) to balance responsiveness and CPU usage.
8. Limitations and security considerations
- TcpLogView shows TCP-level events but doesn’t capture packet contents; for payload inspection use a packet sniffer.
- Process name resolution may fail for short-lived system processes.
- Logging sensitive destinations may expose private information—store logs securely and purge when not needed.
9. Quick reference commands
- Run and save once:
Code
TcpLogView.exe /stab “C:\logs\tcplog.csv” - Save as CSV and exit:
Code
TcpLogView.exe /scomma “C:\logs\tcp_log.csv”
10. Conclusion
TcpLogView offers a simple, low-overhead way to monitor TCP connections on Windows. Use its filtering, export, and automation features to integrate connection logging into troubleshooting workflows or basic auditing processes. Combine with other tools when you need packet-level detail or long-term, centralized logging.
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