Since my original post with the poster over all XE-commands in XenServer I have received a lot of nice feedback (keep 'em coming!!! :)) and over a thousand downloads. This encouraged me to finish up another poster I've been working on for my own (needed it in another project).
If you are segmenting your network and have different features/functions on different nets with a firewall between then it useful to know what ports to open in that firewall. This poster is made to ease that work a little.