I am not sure either, so I will post in the egroupware forum.
I read this, and think it is probably a good idea for neighbors on my server...
"# Limit access to setup to the following addresses, networks or hostnames (e.g. 127.0.0.1,10.1.1,myhost.dnydns.org)
Important, since the Setup-Login has no protection against brute-force attacks (random password attempts). "
I do have the strictly business plan which offers a free ip...if that is what it needs...
thanks for your help. I will write back what I discover, in the event someone else at dreamhost comes across this.