Talk:Firewall, Configuring

Revision as of 20:45, 14 November 2010

ok, so how do you start and stop the firewall? In linux it's a simple "iptables stop" (or start) -- or the redhat dumbed down version is "service iptables stop"....curious how it's done in FreeBSD (haven't had a need to put a FW on one yet...)

--Dave 10:58, 6 Sep 2005 (EDT)

also, typo?

# let everything on your internal network talk to the firewall
        $cmd 01101 allow all from any to any via $iif keep-state 

shouldn't this be

# let everything on your internal network talk to the firewall
        $cmd 01101 allow all from $inside to any via $iif keep-state

$inside to any via $iif

If you're concerned with preventing address spoofing FROM your internal network going OUT to the real world, yes.

I tend to prefer my firewalls to let me-the-user do pretty much anything I want to, as a general rule. It shouldn't really make a whole lot of difference, in practice. --Jimbo 00:13, 7 Sep 2005 (EDT)

starting and stopping the firewall

There isn't any real "omg this stops and starts it" sort of command - you just issue the rule commands you want, either directly from the command line or from a script.

For instance that ruleset in the article? Notice that the first line is #!/bin/sh - you guessed it, it's a Bourne shell script, so to start a firewall with that ruleset you would just run that script. You have to define what a "stopped" condition is before I can tell you how to "stop" the firewall. By "stop the firewall" do you mean "drop all traffic" or "pass all traffic"? --Jimbo 00:17, 7 Sep 2005 (EDT)

Start/stop

In this article, the IPFW is loaded via the kernel, if the firewall was loaded via kernel module, you could issue a "kldunload ipfw.ko".

dunno about running it as a module

Never tried. Everything I read said that you *needed* to build an ipfw kernel, that many things just didn't work properly when you tried to kldload it as a module. I'm not saying I know for a fact that it won't work, just that that's what I've read, and that I haven't tried anything otherwise.

Also, with that said - if you DID build it into the kernel, there IS no such thing as "stopping the firewall" in the manner of kldunloading a module. If it's built into the kernel, the firewall is ALWAYS running - "up" or "down" is a matter of what the ruleset is, not of actually "stopping" a service or daemon. --Jimbo 21:09, 7 Sep 2005 (EDT)

One uncommon way to configure the firewall is find configuration files on the web and test a heavily commented one *carefully*, then if it works one essentially does not need to learn the syntax. Might save a little time...