If We Have To: ftp-proxy With Redirection (Or Divert)

In the base system, load the daemon if you need it

/etc/rc.conf[.local]

ftpproxy_flags=""

/etc/pf.conf

anchor "ftp-proxy/*"

the redirection

pass in quick inet proto tcp to port ftp rdr-to 127.0.0.1 port 8021
pass in quick inet6 proto tcp to port ftp rdr-to ::1 port 8021

In OpenBSD 5.0 and newer, use divert-to instead:

pass in quick inet proto tcp to port ftp divert-to 127.0.0.1 port 8021
pass in quick inet6 proto tcp to port ftp divert-to ::1 port 8021
pass out proto tcp from $proxy to port ftp