Subject: Re: ftp passive mode
To: Luke Mewburn <>
From: Todd Vierling <>
List: tech-userlevel
Date: 04/06/1999 10:26:00
On Tue, 6 Apr 1999, Luke Mewburn wrote:

: I don't consider the current behaviour a `bug', per se.
: If a site has a firewall that doesn't support `passive', their
: ftp server shouldn't respond with a positive response code to
: the effect of ``I support passive, and here's the data...''.
: Their ftp server should return a ``passive not supported'' code.

Like it or not, this happens in an unfortunately increasing rate.  Remember
that I only recently added a `deny PASV' option to our own ftpd(1), and
wu-ftpd doesn't have such at all, AFAIK.

: Otherwise, how do you determine that you have to fallback to active?

Check and make sure that the connection after the PASV succeeded.  This
shouldn't be hard.

-- Todd Vierling (Personal; Bus.