why server hard to access when port set other than 21

BigHead50 · #1 11th Jan 02, 05:43 AM

I have been messing around with access to a ftp server using different port numbers, going from behind a router.. It seems if I use port 21, that almost All people trying to access, Can..
BUT, if I use say port 45000, and 44999 (x-1 data), that no matter how I set up the router or ftp program, Only some can access the ftp...
I have serched for some more info on how to set up NAT to use Non-standard port numbers, with no luck..
I have tryed 3 different routers with the same result, If I use port 21 ONLY, then most all can hook up, But if I use a port like 50000, even if I open the port below for data, and set the router to use non- standard ftp ports, alot of people have trouble hooking up...Especially if they are behind a router also, or going threw a proxi...
I hope someone can understand what I mean and maybe point me to some detailed info on using non standard ports for ftp ??

Thanks for any input and/or info....

SeeYa

Crowdirt · #2 11th Jan 02, 07:12 AM

Hi BIGHEADover50, in simple terms:

Software like IE 6.0 does not seem to know how to cope well if there is a Firewall box in the mix and ports are other than 21.

Actually the Firewall boxes have specific code in them to allow FTP to function through the box like port 80 can. The code is designed around port 21 and does not take effect if the port number is something else.

A few FTP Client programs (Newer versions) seem to know what to do in this case. One that seems to do the trick is FlashFXP, even if you use various port numbers.

g-string · #3 11th Jan 02, 04:18 PM

I'd love to understand fully what's behind this. At home I can access an ftp on any port (dialup=sux). At work I have cable and I'm behind a router, so I can only access ftps on port 21 (and that sux too). I think I saw someone suggest somewhere to try checking "Site uses IP Masq/NAT/Non-Routable IP" in FlashFXP but I haven't got round to trying that yet (and not sure it works, either). Anybody knowledgable on this subject?

g-string.

Crowdirt · #4 11th Jan 02, 04:29 PM

Hi g-string, I expect you know that when making a connection on the Internet the Packets go through a number of Boxes called Routers. Any one of the Routers along the way can Mess with which packets go through and which ones get sent to the "Dirty Bit Bucket".

The Setting "IP Masq/NAT/Non-Routable IP" in FlashFXP can make a difference when connecting to an FTP Server. It will allow you to connect through a NAT Router box (Linksys BEFSR41) when most other things cannot.

Tac2cul · #5 11th Jan 02, 05:27 PM

what ftp server program are ya using?

HotRod · #6 11th Jan 02, 05:50 PM

I too would like to know (learn) more about this. This past weekend was transtioned to comcast.net. Upload speeds went from 138K up to 15K up. Lost my second IP. Went out and bought Linksys BEFSR41 router. Figure speed is slow but still able to help out. Have to run DMZ host to get anything to work right. Tried port forwarding, but no go. What is the best way to set up?

Alll help appreciated

HotRod

g-string · #7 11th Jan 02, 06:08 PM

Many thanks, Crowdirt - that sounds very encouraging. I may even break a golden rule and go into the office this weekend to see if that setting in Flash can let me see my friends' servers.

g-string.

unicorn · #8 11th Jan 02, 06:46 PM

Some things are to learn at RaidenFTPDs support pages at http://www.raidenftpd.com/en/raiden-...-setup-ip.html f eks, or start at http://www.raidenftpd.com/en/raiden-ftpd-doc/index.html. I guess other ftp-server-programmers have similar support pages, but I used RaidenFTPD for a while and then had to learn something from them. Obviously there are different problems with different ftp-clients, and also different problems with different ftp-servers. It is not as straightforward as one would wish...

.unicorn

Crowdirt · #9 11th Jan 02, 08:08 PM

Hi Hotrod, have a read on Page #6 of Crowdirt's Server for some comments on the Linksys BEFSR41 et. al. May answer some of your questions.

BigHead50 · #10 11th Jan 02, 09:33 PM

I use bulletproof server, but also have used servU...
I really don't think that the Server Program is the problem, I really believe the problem is in the NAT box... I just want to find out how to setup a router to use non standard ports, if this is possible....
Like Crowdirt mentions, I understand that most NAT boxes are setup for ftp to run threw port 21, but Many people do not use this port for differnet reasons (hackers,cablecompanys,M$,etc.)My Question is, how to set up NAT so that a nonstandard port can be used ?
Any of the brand name routers web sites I have been over and over, and most do not even speek of this...
I have been to Many forums on broadband, and a couple touch on this but don't really go into depth about it...
If you Can't setup these hard coded NAT routers like Linksys, Netgear, SMC, etc., then I suppose the only real way to do this is a Software NAT program that you set up on a Linux box and program yourself, but I am a year or so away from knowing how to write Linux code...
I also have not the cash for a $5000 cisco box that probably can be programed and filtered to use non-standard ftp ports...
I really am just looking for some place to go and learn more about what I am talking about here, even my MCSE in networking essentials and TCP/IP do not get into this....

Again, thanks for the input and Ideas

SeeYa