Cocoa Packet Analyzer!

Wireshark is the world's foremost network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. It is the de facto (and often de jure) standard across many industries and educational institutions.

tcpdump is a common packet analyzer that runs under the command line. It allows the user to intercept and display TCP/IP and other packets being transmitted or received over a network to which the computer is attached.

SmartSniff is a packet sniffer that capture TCP/IP packets and display them as sequence of conversations between clients and servers. You can view the TCP/IP conversations in Ascii mode (for text-based protocols, like HTTP, SMTP, POP3 and FTP) or as hex dump (for non-text base protocols, like DNS). Application can capture TCP/IP packets on your network without installing a capture driver (works only for Windows 2000/XP or greater).

Ettercap is a suite for man in the middle attacks on LAN. It features sniffing of live connections, content filtering on the fly and many other interesting tricks.It supports active and passive dissection of many protocols (even ciphered ones) and includes many feature for network and host analysis.

Ethereal® is used by network professionals around the world for troubleshooting, analysis, software and protocol development, and education. It has all of the standard features you would expect in a protocol analyzer, and several features not seen in any other product. Its open source license allows talented experts in the networking community to add enhancements. It runs on all popular computing platforms, including Unix, Linux, and Windows.

LANGuardian is the first and only deep packet inspection (DPI) software to provide SMB network managers with root cause information about network and user activity. LANGuardian gives a deeper level of detail than standard flow tools, and is an affordable alternative to premium appliance based DPI tools.

Packet Peeper is a free network protocol analyzer (packet sniffer) for Mac OS X.

tcpflow, a TCP Flow Recorder, is a program that captures data transmitted as part of TCP connections (flows), and stores the data in a way that is convenient for protocol analysis or debugging. A program like 'tcpdump' shows a summary of packets seen on the wire, but usually doesn't store the data that's actually being transmitted. In contrast, tcpflow reconstructs the actual data streams and stores each flow in a separate file for later analysis.

MicroOLAP TCPDUMP is a clone of tcpdump , the most used network sniffer/analyzer for UNIX, compiled with the original tcpdump code (http://www.tcpdump.org/ ), and MicroOLAP Packet Sniffer SDK.

Pirni Pro is a network security tool designed for iOS, and specifically for iPhone and iPod Touch devices. It is capable of intercepting traffic on a wireless network segment, capturing passwords, and regular expressions entered by the user.The core system of Pirni, written in C, is open-source software, and licensed under the GNU General Public License. Pirni Pro is the succeeding version of Pirni, and is commercial software, available in the Cydia Store, for jailbroken Apple devices.FeaturesPirni Pro supports active dissection of all non-ciphered protocols (given that the user has supplied a regular expression for dissection). The application description contains the following: ARP spoof the entire network or any target Watch a live feed over interesting packets collected Manage regular expressions to filter out data, such as site credentials In addition, the software also offers the following features: Password collectors for: HTTPExternal links Root at Everything official website Cydia Link Extensive Tutorial »

AirSnare monitors network traffic for unfriendly MAC addresses and alerts you when a MAC address is found that isn't on the friendly list. AirSnare also monitor DHCP requests from clients.