How to test a Firewall

[ml at bortal.de]

Hello List,

we have set up a firewall and would like to test the setup.
Its not as simple as nust running a portscanner against it because you 
need to have services listen behind the required services.

I am looking for some server-client tool where i can set up a config to 
open up tcp and udp services on multiple port and port ranges.

Can someone recommend such a tool?

Thanks, Mario