bittwist

bittwist (or Bit-Twist) is designed to complement tcpdump, which by itself has done a great job in capturing network traffic. Bit-Twist can regenerate the captured traffic onto a live network (the packets are generated from tcpdump trace file, generating a .pcap file). Bit-Twist also comes with a comprehensive trace file editor to allow one to change the contents of a trace file (bittwiste). Generally, a packet generator is useful in simulating networking traffic or scenario, testing firewall, IDS, and IPS, and troubleshooting various network problems. The Bit-Twist features are: * runs on Mac OS X (and *BSD), Linux, and Windows; * send multiple trace files at a time; * send packets at a specific speed or line rate in Mbps; * comprehensive trace file editor with control over most fields in Ethernet, ARP, IP, ICMP, TCP, and UDP headers with automatic header checksum correction; * append user payload to existing packets after a specific header; * select a specific range of packets and save them in another trace file; * highly scriptable - with proper manipulation you can turn Bit-Twist into an extremely flexible packet generator tool; * if you are teaching Computer Networks classes, you may find Bit-Twist useful as a practical teaching material. It gives your students a hands-on experience to learn various networking protocols etc.