Server is in Germany somewhere in a rack, running Plesk ("psa v7.5.4_build75060413.12 os_FedoraCore 2") on top of Fedora ("Linux 2.6.11.9-050512a").

There is a software firewall on the server, which is part of the Plesk system, which has:

FTP server -- Allow incoming from all

amongst a load of other stuff.

The firewall seems to be described as "the Plesk firewall" :-/

The FTP server is ProFTPD 1.2.10.

The clients, which are sitting here on my desk, NAT'ed behind my DSL router, and which regularly connect perfectly OK to myriad other ftp sites (well OK the mac is new so only a few times), behave thus:

XP
Active
- Connects immediately.
PASV
- Delay of between a few seconds and half a minute and then connects.
(Both via Windows personal firewall)

Mac
Active
- Connects immediately with Mac personal firewall off.
- Fails to connect with Mac personal firewall on.
PASV
- Won't connect at all, regardless of Mac personal firewall settings.

Ok, I give up, what is masquerade?

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