>Can anyone recommend an application to run on Linux that will send >customized Ethernet and IP packets?
After a bit of searching, I stumbled upon this page: http://packetstorm.decepticons.org/libraries/ It's got quite a few tools and libraries listed, but the one that caught my eye was "lcrzoex". From the description: "Lcrzoex is a toolbox for network administrators and network hackers. Lcrzoex contains over 200 functionalities using network library lcrzo. For example, one can use it to sniff, spoof, create clients/servers, create decode and display packets, etc. The Ethernet, IP, UDP, TCP, ICMP, ARP and RARP protocols are supported. Lcrzoex and lcrzo were successfully installed under Linux, FreeBSD and Solaris. This archive contains Lcrzo and Lcrzoex." I've never used it, but it sounds like exactly what you're looking for. - Peter Kristolaitis
