The issue I have currently is with Windows (WindowsXP --> Windows 2003) but I would be interested also in how resolving it in a linux client.
I work with a network split in several subnetworks and there is a firewall between those that is managed by the parent company. Sometimes, when troubleshooting/installing new applications, we find that it does not work due to some port being blocked, and everytime it is a lengthy process to contact the firewall people and agree for a time for a test so we replicate the action and they check the log of the firewall.
As they are pretty much overworked and I would like some more flexibility, I would like to know if there is some way to, from the client, detect attempted connections dropped or denied by the firewall (or at least, all connections from a process/to a server so we can revise them).
I have tried logging things with wireshark, but (if it is the way) I do not know what to look for in the dump. I don't think netstat or PortView would work as these connections are not established.