Ostinato is a network packet traffic generator and analyzer with a friendly GUI. An open-source, cross-platform packet/traffic generator and analyzer with a friendly GUI. It aims to be "Wireshark in Reverse" and thus become complementary to Wireshark.

Ostinato Features:
1. Runs on Windows, Linux, BSD and Mac OS X (Will probably run on other platforms also with little or no modification but this hasn't been tested)
2. Support for the most common standard protocols
3. Modify any field of any protocol (some protocols allow changing packet fields with every packet at run time e.g. changing IP/MAC addresses)
4. Stack protocols in any arbitrary order
5. User defined script to substitute for an unimplemented protocol (EXPERIMENTAL)
6. Create and configure multiple streams
7. Configure stream rates, bursts, no. of packets
8. Single client can control and configure multiple ports on multiple computers generating traffic
9. Exclusive control of a port to prevent the OS from sending stray packets provides a controlled testing environment
10. Statistics Window shows realtime port receive/transmit statistics and rates
11. Capture packets and view them (needs Wireshark to view the captured packets)
12. Framework to add new protocol builders easily

Support Protocols:
* Ethernet/802.3/LLC SNAP
* VLAN (with QinQ)
* ARP, IPv4, IPv6, IP-in-IP a.k.a IP Tunnelling (6over4, 4over6, 4over4, 6over6)
* TCP, UDP, ICMPv4, ICMPv6
* Any text based protocol (HTTP, SIP, RTSP, NNTP etc.)
* More protocols in the works ...

The license of this software is Free, you can free download and free use this network monitoring software.