ftp server not accessable from LAN

May 28, 2005 2 Replies

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Klaus P. Pieper 21 years ago

Hi,

we use a Linksys BEFSR41 Router (Firmware 1.05.03, Apr 29 2004) to connect our LAN with the internet (static IP-address). We are running an ftp server in our LAN. This server is available from the internet via port forwarding without any problem (using the router's static IP address).

However, within the LAN, we can connect only with the local IP address (192.168.x.x).

E.g. if we enter "ftp static IP address" in the workstation's DOS prompt, the ftp server answers and asks for the user name an password. Then the server send a message "230 Login successful". But now, after entering any additional command, the connection hangs and terminates after a while.

The same happens with other ftp clients (e.g. ftp surfer - with and without passive mode).

Some people mentioned already problems with inner forwarding in routers. But I can hardly beleive that this is the root cause as we have no problems with other protocols (smtp, imap or http). It's just the ftp protocol.

Many thanks for your advise.

Klaus

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Frankster 21 years ago

Make sure both ports 20 (ftp data port) and 21 (ftp connection port) are opened.

-Frank

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Demon77 21 years ago

Do you have a software firewall on the computer that you are running the FTP server on?

When I was running a FTP server I had a few things I had to do in order to connect on both my intranet and from the internet -

First - for outside connections coming in - I had my router close all but port 21 on my static IP (those who connected to me would only use port 21 and not both 21 and 20).

Second - I set up advanced rules with my Sygate Firewall to allow incomming communication on port 21 for my FTP server, as well as outgoing (there is another thread that talks about FTP server that there is some really good advanced rules mentioned).

Third - I used a security policy or setting in the FTP server itself in order to allow communication or access to specific internet IP's and through out my internal network. - I had a few select associates from around the globe that were allowed connection/access to my server thus I would use Specific "Allow only these IP addresses" rules with the server.

On the internal and external connection I have no idea how your network is setup but I assume that you are able to have communication between the computers, if your not... this would probably be the source of the error.

Make sure that your IP scheme has the computer that the FTP server on the same Subnet Mask as the computers connecting to it internally, if they are not they cannot see one another and you wont be able to connect. Another thing is to check to see if your router has a configurable firewall that may be blocking communication through your intranet.

Just some thoughts ~

Good luck

Demon

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