Re: HOW TO FTP OVER INTERNET
Protocols and Drivers
HOW TO FTP OVER INTERNET
nijonymi@gmail.com
01-23-2008, 9:35 AM
I have a SNAP-PAC-R1 Opto22 device on my office and 3 computers connected together and to Internet, using a 4 port “Router” and a DSL-Modem. The IOcontrol and IOmanager have the appropriate virtual server configuration on the “router” that let me manage de Opto22 device using “local computers” and “my home computer” over Internet without any problem. Also I can manage text files of Opto22 device without any problem, using Internet Explorer FTP on the office “local computers”.
The problem is using FTP to manage files on the Opto22 device over the Internet using “my home computer”.
Settings:
- Opto22 FTP port: 21
- Router virtual server for FTP:
Protocol: TCP (also try UDP or both)
Private port: 21
Public port: 8021 (also try 21)
- On the “local computers” I use ftp://192.168.0.20:21 to access Opto22 device directory without problems
- Over Internet, on the remote computer I use ftp://officeIPaddess:8021 (Doesn’t work)
Any suggestion?
Re: HOW TO FTP OVER INTERNET
rhernandez
01-23-2008, 11:12 AM
Just one question: With the configuration above, how does your router know what local IP should handle incoming FTP connections?
Anyway, if you've managed to publish PAC's ports 2001 and 22001, I would suggest you to publish port 21 the same way and leave the "router virtual FTP server" unconfigured.
Also, keep in mind that if you publish your PAC's ports, anyone in the world will be able to access it.
Re: HOW TO FTP OVER INTERNET
Nicolas
01-23-2008, 3:28 PM
RH, gracias.
1) Evidentemente el servidor virtual del router esta apuntando a la dirección local 192.168.0.20, solo que se me paso escribirlo en el mensaje anterior.
2) Los parámetros de FTP en el router están iguales que los demás y el “router virtual FTP Server” está des-configurado, por lo que no creo que el problema este ahí.
Será posible que me falte algo en algún parámetro del Firewall de mi antivirus o en el router de mi casa? Aunque no estoy seguro, ya que si he podido hacer FTP a otros FTP servers en Internet.
De paso, gracias por el consejo de no dejar publicado los puertos de Opto22, pero es solo temporal, mientras termino unas rutinas de programación.
Re: HOW TO FTP OVER INTERNET
rhernandez
01-24-2008, 8:57 AM
Nicolas,
Please, lets keep English as our comm language as long as we post outside the International area.
I still think the problem is not in your home router, but in your office. Check the router built-in firewall, it could be blocking some standard ports.
You can also try to work around the firewall: change the PAC's FTP port to another non-standard port (and modify your router config accordingly).
Re: HOW TO FTP OVER INTERNET
Nicolas
01-25-2008, 3:58 PM
The router in the office is a DLINK DI-604. I try everything; also change the PAC´s FTP to a non standard port. PACmanager and PACcontrol works perfect from my home to the office. I’m thinking that is the ISP that is blocking some how, the FTP ports access to the office… NOTE: PACmanager works perfect only inspecting my Opto22 device, but fails to FTP (any maintenance command)…
Re: HOW TO FTP OVER INTERNET
rhernandez
01-28-2008, 11:49 AM
Of course! I've just remembered that you need "something else". FTP uses port 21 for command dialog, the rest of the data, including files and directory-listings, are exchanged using a second port that is negotiated by both peers.
You need to publish this second port, the problem is that it can be anything ... unless fixed some way. This is probably why some routers, like yours, have a special entry for FTP service.
I know it can be worked around, because I have public FTP server working at my office, I just don't remember now how I did it. I'll take a look tomorrow. By now, if you want to go on with FTP you better get yourself a proper FTP-client (like FileZilla) that tells you what goes wrong and what goes right. It should be able to connect and login, it will then try to retrieve a directory listing from the PAC ..and it should fail.