Tcpreplay is a suite of GPLv3 licensed utilities for UNIX (and Win32 under Cygwin) operating systems for editing and replaying network traffic which was previously captured by tools like tcpdump and Wireshark. It allows you to classify traffic as client or server, rewrite Layer 2, 3 and 4 packets and finally replay the traffic back onto the network and through other devices such as switches, routers, firewalls, NIDS and IPS's. Tcpreplay supports both single and dual NIC modes for testing both sniffing and in-line devices. Tcpreplay is used by numerous firewall, IDS, IPS, NetFlow and other networking vendors, enterprises, universities, labs and open source projects. If your organization uses Tcpreplay, please let us know who you are and what you use it for so that I can continue to add features which are useful. Tcpreplay is designed to work with network hardware and normally does not penetrate deeper than Layer 2. Yazan Siam with sponsorship from Cisco developed tcpliveplay to replay TCP pcap files directly to servers. Use this utility if you want to test the entire network stack and into the application. As of version 4.0, Tcpreplay has been enhanced to address the compl