SendIP is a commandline tool to send arbitrary IP packets. It has a large number of command line options to specify the content of every header of a RIP, RIPng, BGP, TCP, UDP, ICMP, or raw IPv4/IPv6 packet. It also allows any data to be added to the packet. Checksums can be calculated automatically, but if you wish to send out wrong checksums, that is supported too.
You can download it from the following link: https://packetstormsecurity.com/files/download/30598/sendip-2.3.tar.gz
Source: https://packetstormsecurity.com/files/30598/sendip-2.3.tar.gz.html