Hi all,

Sorry for the long post.......I have tried everything!

Up till recently I had my 2820n working fine, I could use a web browser to connect to external ftp sites, and indeed I could FTP from an external location into my QNAP NAS behind the router, or my dedicated FTP server. Port forwarding allowed me to have several FTP servers onthe go.

However, since getting a 2nd DSL, or possibly since updating the 2820n firmware, or WIN7..........somewhere down the line FTP has broken.

I can connect to external ftp sites using an FileZilla FTP client (as well as my web browser) but it seems to hang on getting the DIR listing.
Using an FTP client I can see the errors, i.e.

ftp.draytek.pl using plain FTP and transfer mode set to default (as opposed to active or passive)
It'll log in nicely but:

Command: PASV
Response: 227 Entering Passive Mode (92,43,119,45,201,206).
Command: LIST
Response: 150 Opening ASCII mode data connection for file list
Error: Connection timed out
Error: Failed to retrieve directory listing

Trying forcing ACTIVE mode:-
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/" is the current directory
Command: TYPE I
Response: 200 Type set to I
Command: PORT 92,27,50,42,218,116
Response: 200 PORT command successful
Command: LIST
Response: 425 Unable to build data connection: Connection refused
Error: Failed to retrieve directory listing

Here's my 2820n setup:-
Load-Balance policies setup so that all traffic to my NAS (192.168.1.73) uses WAN1 (scr IP start/end)
Load-Balance policies setup so that port range 20 to 21 uses WAN1 (dest port start/end)
Load-Balance policies setup so that port range 55536 to 56559 PASV to my NAS uses WAN1 (dest port start/end)
Load-Balance policies setup so that port range 989 to 990 SSL/TLS to my NAS uses WAN1 (dest port start/end)
........So the above means that all FTP traffic is routed through WAN1
Port redirection setup so that port 1965 forwards to port 21 of my NAS (192.168.1.73)
Port redirection setup so that port 21 forwards to port 21 of my NAS (192.168.1.73)
Port redirection setup so that port 20 forwards to port 20 of my NAS (192.168.1.73)
Ports 20 & 21 opened (just incase)

My domain name DNS records point to WAN1 IP.

Any ideas?............I have googled this to death and tried allsorts but nothing!

More:-
I am able to use FileZilla and FTP internally to my NAS and get a directory listing, but only if I use Explicit FTP over TLS.
If I use the IP of the NAS as the address in FileZilla then I can use plain FTP, but as soon as I use my domain name (thus it goes through the router) I need to use Explicit FTP over TLS.

More:-

Using http://www.g6ftpserver.com/en/ftptest
to connect to my NAS I get:

* About to connect() to mydomainname.com port 1965 (#0)
* Trying 92.27.50.42... connected
* Connected to mydomainname.com (92.27.50.42) port 1965 (#0)
< 220 NASFTPD Turbo station 2.x 1.3.2e Server (ProFTPD) [192.168.1.73]

> USER *****
< 331 Password required for IanJ

> PASS *****
< 230 User IanJ logged in

> PWD
< 257 "/" is the current directory
* Entry path is '/'

> CLNT Testing from http://www.g6ftpserver.com/ftptest from IP 92.27.82.78
< 500 CLNT not understood
* QUOT command failed with 500
* Closing connection #0

curl: (21) QUOT command failed with 500


I have highlighted in red something odd.
92.27.50.42 is WAN1....which is fine.
92.27.82.78 is WAN2....not sure how this is happening, I thought all my rules push all FTP to WAN1 IP.

Ian.

Fixed the web browser FTP problem......downgraded firmware from 3.3.7.1 to 3.3.7
The FileZilla external FTP connections also fixed.
Still having problems connecting to my NAS internally using Filezilla, but I'm sure I just need to tweak a bit more.

Ian.

Sorry to bring this thread back.

But downgrading from 3.3.7.1 to 3.3.7 fixed my FTP connection issues (port 21 was fine, but the transfer/file listing on high ports wouldn't work).