Best way to trace/troubleshoot traffic between Remedy web server and app server.

It probably depends on the problem you're having, but for most of the troubleshooting I need to do, i use

tcpdump

ssldump

On windows, I also use Fiddler for monitoring client traffic to check from that side.

With those tools, I'm usually able to figure out where the problem lies, and narrow down what I need to do.

Hope this helps.