Firewall für FTP nicht ganz offen

Zitat von pureftpd

* Firewalling-> My FTP server is behind a firewall. What ports should I open?First, you have to open port 21 TO the FTP server. You also have to allowconnections FROM (not to) ports <= 20 (of the FTP server) to everywhere.That's enough to handle the "active" mode. But that's not enough to handle alltypes of clients. Most clients will use another mode to transmit data called'passive' mode. It's a bit more secure than 'active' mode, but you need toopen more ports on your firewall to have it work.So, open some ports TO the FTP server. These ports should be > 1023. It'srecommended to use at least twice the max number of clients you areexpecting. So, if you accept 200 concurrent sessions, opening ports 50000 to50400 is ok.Then, run pure-ftpd with the '-p' switch followed by the range configured inyour firewall. Example: /usr/local/sbin/pure-ftpd -p 50000:50400 &Unlike some popular belief, the MORE opened ports you have for passive FTP,the MORE your FTP server will be secure, because the LESS you are vulnerableto data hijacking.If your firewall also does network translation (NAT), you have to enableport forwarding for all passive ports.On the client side, if a client if behind a firewall, that firewall mustunderstand the FTP protocol. On Linux firewalls (iptables), just loadthe ip_conntrack_ftp and ip_nat_ftp modules. On OpenBSD, ISOS andFreeBSD 5 firewalls (PF), redirect all traffic to port 21, to ftp-proxy.