Free tcpdump software for windows

MicroOLAP TCPDUMP for Windows accurately reproduces all features of the original tcpdump by LBNLs Network Research Group, developed for the UNIX systems.
TCPDUMP for Windows is compiled with the Packet Sniffer SDK, so it has many advantages.
Main features:
- does not require any third-party preinstalled drivers;
- works from the single 300K .EXE file;
- supports 1Gbit networks;
- may be launched remotely using Windows Terminal, Radmin , and other remote administration systems.
Version restrictions:
- 30-days trial

Enhancements:
- Version synchronized with original tcpdump 3.9.8 and built with Packet Sniffer SDK 4.0. New feature: support of loopback adapter.

Major Features:
1. Free.

WinPcap is released under the BSD open source licence. This means that you have total freedom to modify and use it with your application, even if its commercial.

2. High performance.

WinPcap implements all of the classic optimizations described in the packet capture literature (e.g., kernel-level filtering and buffering, context switch mitigation, partial packet copy), plus some original ones, like JIT filter compilation and kernel-level statistic processing. For these reasons, WinPcap outperforms other comparable approaches.

3. Popular.

WinPcap is used as the network interface by many tools -both free and commercial including protocol analyzers, network monitors, network intrusion detection systems, sniffers, traffic generators, network testers, etc. Some of these tools, like Wireshark, Nmap, Snort, WinDump, ntop are very well known in the networking community. WinPcap is downloaded thousands of times every day.

4. Tested and Reliable.

Many users have contributed over the years in testing WinPcap on a wide range of platforms, and in finding the most subtle bugs. WinPcap developers are experienced Windows driver writers, and their approach to software development emphasizes rock-solid stability. Remember: a buggy driver means blue screens.

5. Easy to use for the final user.

WinPcap is distributed as a single small executable that runs on every supported operating system. You launch the executable, and from that moment Windows is able to capture and send raw network traffic. It couldnt be easier.

6. Easy to use for the programmer.

Every version of WinPcap comes with a developers pack that includes documentation, libraries and include files needed to immediately start with your own new application. The developers pack contains a set of sample programs ready to be compiled both with Visual Studio and Cygnus, and are available as excellent starting points.

7. Multi-platform.

WinPcap is actively maintained on Windows NT, Windows 2000, Windows XP and Windows Server 2003. WinPcap can also work on Windows 95, Windows 98 and Windows ME, but these OSes are not maintained any longer. Windows Vista has a preliminary support, with some features disabled.

8. Portable.

WinPcap is completely compatible with libpcap. This means that you can use it to port your existing Unix or Linux tools to Windows. This also means that your Windows applications will be easily portable to Unix.
9. Well documented.

The WinPcap manual documents the API and the internals in an easy-to-follow hyperlinked manner. The documentation includes a tutorial that takes you step-by-step through all of the features of WinPcap.

10. Commercially Supported

Are you interested in professional WinPcap support? Do you want a phone number to call when something goes wrong? Do you need help in developing your low-level network code? CACE Technologies can help you!

WareSeeker Editor

Simple UDP Proxy/Pipe application was designed to be an advanced UDP proxy/datapipe/packets forwarder and modifier with multiple functions.
Multiple clients allowed (you can connect many clients you want to this proxy), creation of ACP files (tcpdump capture files, just like a sniffer), packets forwarding (chat style, each packet is forwarded to all the other clients and server connected), packets injection (the tool opens a specific UDP port where you can send your customized packets which will be sent to the server), hexadecimal visualization and plugins support for the modification and visualization of the packets with some example plugins already included (Zdaemon huffman, Doom huffman, Half-life decoding and one for the replacement of the text strings).
Plugins (which work on both Windows and Linux) are very basic to create and use, just take a look at example_sudp.c for more informations .