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Old 07-25-2003, 11:01 PM  
Junior Member
Join Date: Jul 2003
Posts: 3

dear MxxCon

on *nix systems ports 1-1024 are "privileged ports", meaning you need root account to access those ports, which is often not the case for ftp servers.
ok, i understand, didnt know that but not all are *nix ftps and if you are connected to one it could possibly be that the used ftpd have the limitation to denie acces on ports under 1024 OR NOT.
all of the boxes i have in my bookmark folder do not have this limitation.. i just found some public university and company ftps with this restriction (of course not all)

its only conditioned by the rights not by the technical side! ill show you why:

plus, you need to know how PORT or PASV(reply) commands are formed.
for example we have
PORT 192,168,150,80,14,178
obviously 192,168,150,80 are 8bit octets of your ip address.
14 and 178 are not plain port numers.
to find the actual port multiply the fifth octet by 256 and then add the sixth octet to the total. thus in the example above the port number is ( (14*256) + 178), or 3762.

and as you can image, the lowest valid PORT number you can have is x,x,x,x,1,1 or in other words 257
as i said i connected my box to some *nix ftps (and of course windows ftps too) allways with port 80 as ACTIV port. most ftps worked perfect and some ftps not.

the working result look like this:

PORT x,x,x,x,0,80

check: (0*256) + 80 = Port 80

so, what do you think? i would say you made a little misstake bro. its possible to use all ports from 1 - 65535 as activ data port...
you can fill port 1 - 255 with x,x,x,x,0,1 - x,x,x,x,0,255
and after that
port 256 with x,x,x,x,1,0 and port 257 with x,x,x,x,1,1 etc etc

the not working result looks like this:

PORT x,x,x,x,0,80
500 Illegal PORT command.
425 Can't build data connection: Connection refused

that was a *nix ftp with this limitation..

so now i ask you: why denie this feature if its only a rights limitation and not a technical restriction

i hope you understand me and further i hope you or the ffxp coder will implement this little nice feature

thank you for your audience


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