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Re: Cannot connect to ftp server

Posted: 2020-06-19 22:18
by boco
What Encryption do you use to access the server? If connecting to 21, you must use FTPS Explicit. For port 990, you must use FTPS Implicit.

The recommendation is to only connect to port 21 (Explicit) not use port 990 (Implicit) at all, as the latter is not a formally standardized connection type.

Could you fancy a screenshot of the data port forward rule in the router?

Re: Cannot connect to ftp server

Posted: 2020-06-20 10:40
by James_liv
Morning,

Please find these screenshot.

One from the FTP over TLS and the other two from the virtual server and port triggering of the router.

Does this help?

Re: Cannot connect to ftp server

Posted: 2020-06-21 01:23
by boco
1. Please kill Port Triggering rules 1 and 5 - the FTP ones. Port triggering doesn't work for FTP and these rules will mess everything up.

On a second note, for each of your duplicated forwarding rules (Virtual Server vs. Port Triggering), use one or the other, never both!


2. You can set the protocol for the FTP rules in Virtual Servers to TCP. FTP makes no use of UDP, and having unnecessary protocols exposed is not recommended.

3. The 990 -> 21 rule is still wrong.

Port 21 expects a plain, unencrypted FTP connection that is then upgraded to TLS by sending AUTH. Port 990 expects an implicitly encrypted connection from the start. Never mix both kinds of connection, or client and server will not understand each other.

Re: Cannot connect to ftp server

Posted: 2020-06-22 07:21
by botg
Check your range forward, it looks as if you have forwarded 50000-50099 to the single port 50000. You need to forward it to 50000-50099.

Your your router cannot forward ranges to ranges, manually add 100 consecutive single port forwards.

Re: Cannot connect to ftp server

Posted: 2020-06-22 08:19
by boco
@botg: That's how some routers display it. For the remote range, the display is complete, but for the local range, only the start port is shown. It usually works, nonetheless.

Re: Cannot connect to ftp server

Posted: 2020-06-23 11:31
by James_liv
Yeah, it's forwarded the only way that is possible.
I initially thought the same thing but that's how my router forwards the ports.

I've been away with work for a couple of days but I'll try your suggestions when I get home tomorrow night.

Thank you. Your help is very much appreciated.

Re: Cannot connect to ftp server

Posted: 2020-06-23 21:39
by James_liv
Afternoon,

So, got home early so trying to get this working.

See attached screen shots of how it's setup.

Port 990 now gets me to the welcome message but then gives error...

421 Login time exceeded. Closing control connection.

If I use port 21 I get nothing at all.

Any ideas?

Re: Cannot connect to ftp server

Posted: 2020-06-25 07:27
by James_liv
Hi,

I'm still struggling with this if anyone has any other advice?

Thanks in advance.

Re: Cannot connect to ftp server

Posted: 2020-06-25 09:26
by botg
Try a different router.

Re: Cannot connect to ftp server

Posted: 2020-06-25 12:24
by James_liv
As I said right at the start. The ftp server was working absolutely fine and had been doing for a while.
I had to reinstall windows and this is where the problems started.

There's absolutely nothing wrong with the router.

Re: Cannot connect to ftp server

Posted: 2020-06-27 19:03
by James_liv
I take it we're all out of ideas on this?

Just completely bizaare that it suddenly won't work anymore.

Any ideas or help fixing it would be appreciated.