Fetching distfiles with ftp on a host sitting behind a NAT gateway (with
builtin ftp proxy) is working fine from most file servers on the Net.

But with a few remote servers, ftp is stopping after login and cd in the
remote file server :  no data is received, the progress bar is showing 0%
and there is apparently no timeout to the stopped transfer.
On the other hand, fetching the same distiles from the same remote servers
on a host that is directly connected to the Internet (i.e. without NAT and
builtin ftp proxy) is always working fine.

Is this problem related to the NAT or to the builtin ftp proxy ?
Is there a workaround ? (especially related to the use of pkgsrc)

Thanks,

Jean-Pierre HOFER