Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 15 Sep 1999 14:11:19 -0700 (PDT)
From:      "Eric J. Schwertfeger" <ejs@bfd.com>
To:        Ken McGlothlen <mcglk@serv.net>
Cc:        questions@FreeBSD.ORG
Subject:   Re: A brief tutorial on closing the barn doors?
Message-ID:  <Pine.BSF.4.05.9909151401330.15395-100000@harlie.bfd.com>
In-Reply-To: <87g10f29rl.fsf_-_@ralf.serv.net>

next in thread | previous in thread | raw e-mail | index | archive | help
On 15 Sep 1999, Ken McGlothlen wrote:

> As time goes on, my general lassez-faire attitude toward system security in the
> home is gradually changing.  In the face of 24/7 net connections, I'm beginning
> to think that the free Uni distributions should default to "nothing open."

Actually, FreeBSD doesn't come that open.  Just basic functionality.

port	where to turn off
ftp	inetd
telnet	inetd
shell	inetd
login	inetd
finger	inetd
comsat	inetd
ntalk	inetd
sunrpc	rc.conf
smtp	rc.conf

Usually, I turn off shell, login, comsat, ntalk, and sunrpc.

> So where do I start?  I have a FreeBSD box hanging off a DSL connection.  Where
> do I look for information on how to start locking the doors?

I'd say the first step is to determine exactly what is open.

netstat -a | grep LISTEN 
netstat -a | grep ^udp

These will list ports that can be connected to.  From there, it's a matter
of 1) commenting lines out of /etc/inetd.conf, 2) stopping unneeded
daemons from starting, and 3) firewalling those services that you only
want to use to talk to yourself with.

Actually, for #3, I usually deny everything below port 1024, and
explicitly allow those services that I want to be available to everyone.



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.05.9909151401330.15395-100000>