yes, it's the same server.
in any of your howtos regarding debian setup you mentioned a /etc/hosts-file like
127.0.0.1 localhost localhost.localdomain
trying 'telnet localhost 21' and 'telnet example.net 21' directly on the machine was the same - different banners.
it's not a problem at all - will use vsftpd. but being new to linux-setup i'm willing to learn. but i couldn't figure out, where's the problem so i asked here.
if i can provide any further information, i will do so.