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wolf1oo Joined: Jul 01, 2008 Posts: 11 Other Topics	Posted Jan 23, 2009 at 4:31:12 AM Subject: FTP Help Hi, I have an FTP server on a Fedora box I have been running for a few months now. The only problem is that windows computers can connect to it through the normal IP of course, but for the strangest reason my desktop linux cannot connect through the normal IP, but rather only the local IP (192.168.blah.blah). I have already checked the firewalls and other network settings, but its all clear, firewalls are off and all that but still does not work. I ran netstat with a connection to the FTP server through the local IP and through the external IP, because it DOES connect to the server at first through the external IP, but then when you try to execute any commands it returns error 425 "Unable to Build Data Connection". It really is troubling me. Here is the output regarding the two connections from netstat: [code=xml] tcp 0 0 X.X.X.X:60040 X.X.X.X:ftp ESTABLISHED tcp 0 0 X.X.X.X:46725 c-X-X-X-X.hsd:ftp ESTABLISHED [/code] For some reason the "c-X-X-X-X.hsd:ftp" is worrying me, because I think it ought to look like the local connection of "X.X.X.X:ftp". Any help would be GREATLY appreciated.
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Rubberman Joined Jul 30, 2007 Posts: 944 Location:40 miles west of Chicago Other Topics	Posted: Jan 23, 2009 4:48:43 AM Subject: FTP Help As I remember (it has been a LONG time since I got into the internals of FTP and Telnet), Windows is a brain-dead implementation of FTP and Telnet protocols. Linux on the other hand, is much more faithful to the White Book RFCs. What that means is that Linux uses (I think) a separate socket for the data connection than the control channel, where Windows might not (I'm not entirely sure of this last part, but I remember having problems like this in the dark, distant past - like in the late 80's and early 90's, although my concerns were Unix and Windows). Is it possible that your firewall rules are blocking the port that the Linux client FTP is trying to use for the data channel, which would be different from the control channel? Sometimes real fast is almost as good as real time. Remember, Google is your friend!
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bsulli Joined Jan 06, 2009 Posts: 2 Other Topics	Posted: Jan 23, 2009 4:12:50 PM Subject: FTP Help One place you call it local and normal IP and another you call it internal and external IP so I'm assuming an external/Public IP. There is a lot of info missing such as does the FTP accept anonymous login, require user/password. Who's FTP server are you using. There are several that can be installed on Fedora. If external is there another router between the ftp server and the external IP? Are you using Active or Passive FTP settings? Sounds like active which requires more configuration to support to external/public IP's http://slacksite.com/other/ftp.html Usually the problem is port 20 from the outside world. Also the Linux clients local firewall maybe turned on, plus the port 20&21 configuration. There are two separate issues to consider and that is there are two channels required. One command/control and one data connection. Sounds like command works but data doesn't. The greater question is are you going to be passing customer data to this server? If so FTP passwords fly in clear text, major no no in today's world. I only use ssh servers for my customers. I will not support standard FTP to a public IP address for security reasons.
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wolf1oo Joined Jul 01, 2008 Posts: 11 Other Topics	Posted: Jan 23, 2009 10:47:19 PM Subject: FTP Help Well, I did indeed mean internal and external, i just always think of it as local. Anyways, it is running anonymous and a login system, and the actual ftp server is ProFTPd. It is a Passive server. Is there any way to check what the linux client for ftp uses as a port? And no, I am not using it for any customer data or anything that needs safety.
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proopnarine Joined Apr 03, 2008 Posts: 590 Location:San Francisco Other Topics	Posted: Jan 24, 2009 3:48:45 AM Subject: FTP Help Are the Windows machines also on the internal network? If not, then it could be as simple as internal machines not being allowed to use external IPs, or some issue with the nameserver database. Is your FTP server and Linux machine behind a firewall, and is the system administered by Windows servers? Take the red pill Climate Change Blog Food Weblog
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wolf1oo Joined Jul 01, 2008 Posts: 11 Other Topics	Posted: Jan 25, 2009 2:44:43 AM Subject: FTP Help the system is administered by my linux server, and windows machines both on the internal and external IP's can connect. My linux machine is not behind a firewall, and my ftp server is behind the normal router NAT firewall, but the normal ftp port is forwarded (21).
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proopnarine Joined Apr 03, 2008 Posts: 590 Location:San Francisco Other Topics	Posted: Jan 25, 2009 3:23:53 AM Subject: FTP Help Hmmm, odd. The linux client really shouldn't care what port the server is using, certainly not in terms of the IP anyway. Can you reach the machine from a Linux box that is not on that network, using the external IP? My guess is that you can. Take the red pill Climate Change Blog Food Weblog
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wolf1oo Joined Jul 01, 2008 Posts: 11 Other Topics	Posted: Jan 26, 2009 2:38:08 AM Subject: FTP Help unfortunately I am unable to test that exact aspect, however much i wanted to, because none of my friends use linux and I only have home computers with linux on them. But even if they did work, that would leave the question as to why mine does not work, seeing as I have turned off all security and everything (wasn't that much in the first place) and it still won't send commands, only connect.
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