Netcat's UDP scan shows us nothing. This output indicates port 19315 is open, but it is the same if the server is down or if the firewall is closed.
Here is a hex dump of the outgoing packet we captured with Ethereal. We'll edit it to remove the packet headers, leving only the data.
Now when we send it through netcat, we get a quick reply from the server. Although mostly gibberish, it is enough to tell us the Keyserver program is running and we can connect across the network and firewalls.