FTP server Blocked port 21 question

I had a FTP server running a while back and when ATT took over the service, port 21 got blocked, which screwed the FTP pooch.

Just for fun, I started up the Server again and started playing. Port 21 is still blocked, but port 20 is not. When I type in ftp://domain I get the user/password for my server, even though the server is set to port 21 and the router is set to pass port 21, but not 20.

Even though I was encouraged that I could "Reach" my server though port 20 by doing a fto://domain:20 ,and the server got a "List" command, the computer I was requesting from only got a swinging flashlight abd explorer came up with a server error after a bit.

Is there a workaround for the blocked port 21 issue.

Why when I specify port 20 from the requesting computer, does it "see" the server on port 21?

You don't have to run ftp on 21, you can put it on any port you want, depending on the OS. Just when you ftp in you have to specify the port number.

RichP said:

You don't have to run ftp on 21, you can put it on any port you want, depending on the OS. Just when you ftp in you have to specify the port number.

Click to expand...

What other common ports are used?
When I set the Server to port 20, not blocked, it doesn't work at all when polled at port 20.
When I set the Server to port 21, blocked, I can access the server by polling port 20, but only to the extent of the menu and swinging flashlight bit.

OS is XP on the computer asking for FTP, and 98 on the Server.
I tried port 8080 and got the same result. Sign in box, then a swinging flashlight.
The server lists the last request as "LIST". Server is told it is taking to a UNIX system, not DOS.

Remember that FTP uses 2 ports, not one. One is control, one is used for data transfer.

ChiXJeff said:

Remember that FTP uses 2 ports, not one. One is control, one is used for data transfer.

Click to expand...

I was starting to suspect...

Do the port numbers have to be consecutive?

Zuki-Ron said:

I was starting to suspect...

Do the port numbers have to be consecutive?

Click to expand...

Probably dependent on ftpd implementation. You'll have to check your ftp daemon docs to figure out how to set control and data ports.

Can you use an FTP client instead of explorer? That may give you less grief.

Hoboken Hobo said:

Can you use an FTP client instead of explorer? That may give you less grief.

Click to expand...

Indeed! If you're using Firefox, try the FireFTP add-in. It's da good chitz!
:clap:

Some good points towards the top, and I looked into them.

It appears FTP uses 21 and 20 or any pair as communication and data. It also used two other ports dynamicaly and it chooses them by itself.

I am running XP Firewall on the client machine and it turns out it is blocking the ports that the FTP Server and Client use dynamicaly. I proved that out by dissabling Firewall and in Explorer, typing in "ftp://mydomain.org:20 and it worked OK.

Mind you that AT&T has port 21 blocked and the server is set to use port 21. If I set the server to use port 20, it stops working.

So, I have to find the range of ports that the FTP programs are using and enable them in Firewall.

I am still stymied about how it is working at all since I am calling the wrong port.