FXP transfer fails

[titteuf]

Hi,
I noticed a strange behavior while FXPing.

configuration:
* FlashFXP v 3.0.2 , build 1044, Evaluation version (will buy if this works...)
* OS : WinXP Pro SP2
* Running on a LAN
* No firewall
* No Antivirus
* Network : 100 Mbits/s
* FTP server(s) : BPFTP Server - other side unknown

IP configuration:
client: 192.168.0.251
trying to FXP from 192.168.0.112 (left side in flashFXP)
to : 192.168.0.148 (right side)
(all write authorisation have been checked, servers allow FXPing)

when I transfer I have, in flashFXP logs:
***************************************
[L] PASV
[L] 227 Entering Passive Mode (192,168,0,112,196,29).
[R] PORT 192,168,0,112,196,29
[R] 200 Port command successful.
[R] STOR welcome.msg
[R] 150 Opening data connection for welcome.msg.
[L] RETR welcome.msg
[R] 425 Cannot open data connection (10060).
***************************************

So I have the correct command:
[R] PORT 192,168,0,112,196,29
sent to the 192.168.0.148 server, but when I check the FTP server logs, I see:
(192.168.0.251) > PORT 192,168,0,251,19,138

I check a lot of time, this is the same commande, same time, no doubt about that, but FlashFXP doesn't write in the log what is really sent on the network
I used a packet sniffer to check the packets, and it's really the client IP (computer running flashFXP) which is sent in the PORT command, not the other server IP.

I tryed the transfer with 2 telnet prompts, writing the correct commands by hand, and the transfer worked, so I don't think my packets are modified by windows or an other software, nor are blocked in any way, FlashFXP is really not sending what it says.


I hope somebody will be able to understand my english...
Thanks
Tit

[bigstar]

Sounds like you have a NAT based firewall/router, ICS that is modifying the ftp commands sent by FlashFXP.

What you see in the status window for the PORT command is the exact same text sent to the socket.

One way to confirm this is to run the ftp servers on a non-standard port or use SSL/TLS rather than a standard connection.

[titteuf]

So, next step:

I ran my FTP server on port 211, it worked!
So I put it back on 21, but then I used a telnet:
************************************
cwd upload
250 CWD command successful. "/upload" is current directory.
port 192,168,0,148,17,18
200 Port command successful.
stor temp.xls
150 Opening data connection for temp.xls.
226 File received ok.
************************************

how a telnet can work, the "PORT" command isn't modified, but with FlashFXP, the PORT command is modified...

BTW, I tryed also to desactivate a windows Service. I guess it's called "Firewall/Internet connexion sharing" in english. And then it worked!

I used the ICS some time ago, but I don't anymore... I desactivated it and it still doesn't work...

well, the main question is : why telnet works and flash FXP doesn't??

Thank you for your help

[titteuf]

just understood... telnet is send character per character.. windows cannot catch it...

but so, everybody under windows XP SP2 can't use flash FXP unless to desactivate the firewall??? that sound strange... :'(

any idea?

[MxxCon]

Originally posted by titteuf
just understood... telnet is send character per character.. windows cannot catch it...

you know, i think you stumbled on something great here.
i think this might be a way to fool routers from performing NAT on ftp commands..
flashfxp could send PORT command in 2 or 3 packets

[titteuf]

in fact I wasn't thinking about that, but it would be a great option for flash fxp to be able to do so!
posting it right now in suggestions!

[Hetfield]

I hope you're kidding, because this is the most ridiculous thing i have ever seen on this board

[titteuf]

Sorry I was not.
If you think that a way to make FlashFXP working on windows XP SP2 is a ridiculous thing, it's your opinion.
For now there is a pb and I have to desactivate the firewall to be able to FXP.
In my opinion it's more ridiculous to remove a firewall when you are on the internet than to find the way to use a program with this firewall, even if the solution is stupid.

[Hetfield]

And you really think everybody with Windows XP SP2 with the internal firewall enabled are unable to FXP? That wouldn't be a very good thing . There are *alot* of people who have this combination running ok (including myself) so i think your solution lies somewhere else.

Just my 2 cents

[titteuf]

So, let's just test that. I asked a friend before telling so, it doesn't work on his computer. It doesn't work on both of mine either, and worked properly with SP1.

Is the firewall enable on the connexion you use to FXP? how many network interfaces?

I'm connected throught a LAN, does it change something, etc...

I'd like to now how you do if it really works with you.

[MxxCon]

Originally posted by Hetfield
And you really think everybody with Windows XP SP2 with the internal firewall enabled are unable to FXP? That wouldn't be a very good thing . There are *alot* of people who have this combination running ok (including myself) so i think your solution lies somewhere else.

obviously not everybody experience this problem, but there are quiet alot of hardware routers that do NAT which break FXP transfers.
this trick might enable them to fxp.

stand by for more details

[titteuf]

Hi,
just wondering what's up about this.

Do some people with the windows XP SP2 and the windows firewall enable (and enable on the connexon using the FXP) can FXP. and do you have other networking interface, connecting throught dial up or high speed, etc...
?

thx for comparing with me (people not working...)

[Hetfield]

It looks like i was a bit too quick in my judgement because i heard that option of "breaking down" the port commands can actually work to fool some NAT routers. I have no idea if bigstar will add this feature though. As an example of somebody who has XP with SP2 and the network configuration:

Just a simple switch attached to lan which is connected to the internet. It doesn't make much sense to tell all details here because every combination you can think of seems to work just fine here.

[uht_magro]

I have the same problem with sp2, with sp1 i havo no problems with fxp, but with the firewall of sp2 active a cant do fxp, i ha've tried to enable all options on firewall of sp2 and no results.. the only way i found is to turn off the firewall when i want to fxp...
anyone knowks another way (using the firewall of sp2 of course)

regards

[titteuf]

From built 1045, you can use a new feature:
"To enable this feature you must open your flashfxp.ini with notepad, and add the following entry under the [main] section "FxpNatTrick=1" (without quotes)"

this works for me, and should with you too. There is no other way to bypass Win XP SP2 firewall.

Tit