...intriguing.

from a w32 box outside firewall, no proxy: a variant outcome:

C:\>ftp ftp.perl.org
Connected to ftp.cpan.ddns.develooper.com.
220---------- Welcome to Pure-FTPd ----------
220-You are user number 4 of 512 allowed.
220-Local time is now 08:12. Server port: 21.
220-Only anonymous FTP is allowed here
220-IPv6 connections are also welcome on this server.
220 You will be disconnected after 15 minutes of inactivity.
User (ftp.cpan.ddns.develooper.com:(none)):
230 Anonymous user logged in
ftp> cd pub                              # 
250 OK. Current directory is /pub
ftp> ls                                  # dir also OK
200 PORT command successful
150 Connecting to port 1548
CPAN
FreeBSD
OpenBSD
WM
analog
apache
exim
fedora
gimp
gnu
isc
mysql
openssl
postfix
proftpd
proftpd-www
python
qmail
sendmail
squid
vim
webalizer
webalizer-www
xemacs
xemacs-www
226 25 matches total
ftp: 204 bytes received in 0.02Seconds 12.75Kbytes/sec.
ftp> quit
221-Goodbye. You uploaded 0 and downloaded 0 kbytes.
221 Logout.

C:\>
[download]

But, same box, the very next iteration gets Welcome to viaVerio's San Jose, CA, USA CPAN FTP server! with a different organization of /pub and different content.