Detecting DC++-Hubs per NMAP

[Tobias Braun <logarithmenlord () googlemail com>]

Hello,

I want to detect hosts running DC++-Hubs in a wide range of hosts. I
know that those are usually running on 411/TCP, so I tried a SYN-ping on
this port, is this correct?
Furthermore, in case the hub is running on another port than 411/TCP,
how to detect the hub?

Greetings!