unauthorized FTP attempts

[<debian-isp@ghost.net.cfw.com>]

Hello ISPers,
Recently (within the last couple months) I've noticed a big increase of
people that are trying to ftp into my debian machine. I have logchecker
running and notice whenever there is an attempt to connect. I was thinking
in my mind that they may be trying to connect to see which version of ftpd
I am running? I remember reading about a security hole in one of the old
ftp servers. I've updated mine to the stable, but think this is what they
may be trying to do.

Also, I was wondering what kind of action (if any) we should take in
stopping this type of thing? (contact the isp) ?

Anyone have anything to say about this?

Thanks,

D Ghost