Can't connect to FTP

[seismik]

Hi, I run Blackmoon FTP server, the free version on my PC at home so that I can easily transfer files back and forth from that machine. Pretty standard stuff, it's running on port 21 and I've made my PASV range 8000-9000. On my Linksys BEFSR41 router I've got UPnP turned on, and I've also created port forwarding rules for port 21 and 8000-9000. Everything was working great and then suddenly I've been unable to connect. My IP address is definitely correct, when I open an FTP connection from my local machine it works great... all my other networking runs great -- just the FTP won't work. When I attempt to connect I get the 'Connected to FTP' message, but nothing after that and eventually it times out and dies. I've reinstalled Blackmoon FTP Server, made no difference, exactly the same problem. I don't know what else to check, firewall in Windows XP Pro is turned completely off, the Linksys seems to be working correctly, all the Blackmoon settings are correct... what could be preventing me from connecting properly as I used to?

Thoughts?

Thanks,

seis

 

[Need4Speed]

what client are you using? is it set for PASV?

 

[seismik]

FlashFXP, it's set for PASV and was working correctly. Even using ftp from the command prompt I never get a logon prompt... says Connected to XXX.XXX.XXX.XXX and then times out eventually.

 

[Mucman]

I'm not familiar with that FTP software, but it sounds to me like the problem is that your FTP server is not reporting your external IP when establishing the PASV connection. What's happening is the following:

External IP : Hello EX_IP, port 21
(router port forwards to your FTP Server)
FTP Server: Hello, I see you want a PASV connection. Please connect to IN_IP, port (something between 8000-9000).
External IP : ok, Hello IN_IP, port 8002
External IP : Hello?
Extrenal IP : Fine be that way

What happened is that your FTP server passed the external client it's own internal IP. The FTP server needs to spoof this IP with your external IP address. The only FTP server I'm familiar with is PureFTP and it can do this no problem.

 

[seismik]

Thanks Mucman, unfortunately that's not it either. Blackmoon DOES support spoofing my external IP address, and it's set correctly. Strangely, because my ISP changes IP addresses on me from time to time I have been late on changing the spoof address to match, yet everything still worked just fine. Now, regardless of what I put in for the external IP I still get nothing. I will remove my router from the equation this evening and see if it works straight thru, start eliminating possibilities, truly odd problem.

seis

 

[MtnMan]

Perhaps your ISP is blocking incoming TCP Port 21 now. Configure your server to accept connections on a different port then try again.