This is a question that always comes up. FTP is a multiple port protocol, port 21 is only the command port and if you don't have access to the other ports that are needed you end up with issues like you are having. The two modes are 'Standard' and 'Passive'. For an explanation I will quote a website. Quote: "Standard mode FTP clients first establish a connection to TCP port 21 on the FTP server. This connection establishes the FTP command channel. The client sends a PORT command over the FTP command channel when the FTP client needs to receive data, such as a folder list or file. The PORT command contains information about on which port the FTP client receives the data. In PORT Mode, the FTP server always sends data from TCP port 20. The FTP server must open a new connection to the client when it sends data. Passive mode FTP clients also start by establishing a connection to TCP port 21 on the FTP server to create the control channel. When the client sends a PASV command over the command channel, the FTP server opens an ephemeral port (between 1024 and 5000) and informs the FTP client to request data transfer from that port. The FTP server responds to the request by using the ephemeral port as the source port for data transfer. When this occurs, the FTP server does not need to establish a new inbound connection to the FTP client." Cheers Simon -----Original Message----- From: owner-nzlug@linux.net.nz [mailto:owner-nzlug@linux.net.nz] On Behalf Of Edwin F Sent: Monday, 8 November 2004 21:04 To: NZLUG Subject: [nzlug] Problems with proftpd Hi, I'm just playing around with proftpd and i can access it from just about everywhere in the LAN anonymously. But when i try it from 'outside' then it requires a username and password. My computers behind a smoothwall firewall, but i have already set that to redirect port 21 to my computer. I tried disabling the firewall on my computer (guarddog - i think its just a fontend for iptables or something) and its setup to accept any anonymous logins, 3 simultaneous instances (2 multiple connections), and im positive that its set up to use port 21. If i missed any details out, just say and ill post it within a day but for now, any suggestions??? ------------------------------------------------------------------- To remove yourself from this list, email nzlug-request@linux.net.nz with "unsubscribe" in the body of the message. ------------------------------------------------------------------- To remove yourself from this list, email nzlug-request@linux.net.nz with "unsubscribe" in the body of the message.
|
If you have any questions or comments about this page, email the
Webmaster Copyright © 1998-2002 Linux.net.nz |