I know I've solved this one a million times, but I can't seem to find the right answer on any weblink. I guess I'm going to have to write the answer down this time.

I've installed a new linux slackware computer. I want to ftp to this computer using proftpd. I've enabled proftpd in inetd.conf. /etc/proftpd.conf specifies:

ServerType inetd
DefaultServer on
Port 21
Umask 022
MaxInstances 30
User bison
Group bison
SystemLog /var/log/proftpd.log
TransferLog /var/log/xferlog

<Directory /*>
AllowOverwrite on
</Directory>

I don't want anonymous ftp and the ftp user is listed in /etc/ftpusers. Does the ServerName matter in proftpd.conf? I've just got it set to an arbitrary string.

I've rebooted.
I can connect to port 21 remotely via telnet but if I try using ftp, I never get a login promt. It waits a while, then I get

421 Service not available, remote server has closed connection

I see nothing in any log files.

I can ftp locally.

What am I doing wrong ... again?

Hi,

Please note that it's the inetd daemon that listens on port 21, so actually this is who responds to your telnet. In a normal ftp connection, it should pass control to the ftpd server.
Could you post the inetd.conf line where you call proftpd?
Also you can comment out that line, restart inetd, configure proftpd as standalone, start it and see if you can connect

Regards

Duh! I figured it out. It was a router issue. I'll have to say IMOH the Apple airport extreme is not all that easy to set up. The port forwarding dialog showed that I had ssh, http and ftp all forwarded. ssh and httpd worked fine, so I didn't think it could be a router issue. The problem is, the port forward dialog shows the forwarded ports (actually, descriptions, not the actual port numbers 22, 80, 21, respectively), but it does NOT show to which IP these are forwarded. You have to click on an Edit button which takes you to a subordinate dialog. This thought finally occured to me and I drove to the office in the middle of the night to check it out. Sure enough, the ftp port was not forwarded to the linux host, but the others were! I forwarded ftp to the correct host and voila!

Problem solved.

Thanks for your patience on this one.