Developer's description:

Colasoft Packet Builder is useful tool used for creating custom network packets, you can use this tool to check your network protection against attacks and intruders. Colasoft Packet Builder provides you very powerful editing feature, besides common HEX editing raw data, it featuring a Decoding Editor which allows you edit specific protocol field value much easier. In addition to building packets, Colasoft Packet Builder also supports saving packets to packet files and sending packets to network. Colasoft Packet Builder provides several kinds of common-used packet - ARP Packet, IP Packet, TCP Packet and UDP Packet. All packets and their decode information are editable. Users can create a most poplar packet according to the template provided by Colasoft Packet Builder conveniently.