I'm attempting to get my proftp server to be access able from outside my local network.

The only way I can get proftpd to accept connections from the outside world is to run it on port 22 (after stopping my sshd server). This forwarding works fine.

When I try to run it on 21 and I attempt to connect to it, it just hangs. I have set up the port forwarding on my router. I have even attempted to set that specific server as a DMZ.

With the target machine as a DMZ, here is an nmap result from a server outside my network:

PORT STATE SERVICE
21/tcp filtered ftp
22/tcp open ssh
25/tcp filtered smtp
80/tcp filtered http
110/tcp filtered pop-3
135/tcp filtered msrpc
136/tcp filtered profile
137/tcp filtered netbios-ns
138/tcp filtered netbios-dgm
139/tcp filtered netbios-ssn
443/tcp filtered https
445/tcp filtered microsoft-ds
1433/tcp filtered ms-sql-s
1434/tcp filtered ms-sql-m
1720/tcp filtered H.323/Q.931
6667/tcp filtered irc
10000/tcp open snet-sensor-mgmt

I don't see why it claims it is being filtered but it certainly seems to act like it.

I'm not running a firewall on the DMZ box either.

Any help is greatly appreciated.

Cheers,
Mark

Is it possible that your ISP is blocking it? Are you running any iptables firewall at all?