slackware firewall for internal windows network

[George Toft]

Hi Jeff,

It looks like you've got the hardest part done.  Activate IP 
Forwarding with this:
# echo 1 > /proc/sys/net/ipv4/ip_forward

You should put the above line in a script so it gets run after each 
reboot as it is not persistent.  Here is a good place for the slackers 
to tell us the elegant method under slack.

Here is link to a good firewall script:
http://georgetoft.com/linux/firewall/index.html
skip down to the section that says "/etc/init.d/firewall"

You may have to make some adjustments so the Windows boxes can
access the nameserver.  There are some other security tidbits in 
there, too, that I highly recommend.  See also:
http://georgetoft.com/security/index.html

Set up the windows boxes to use your 192.168.x.x IP as the default
gateway and DNS and you should be good to go.


George



Jeff Barker wrote:
> 
> I'm setting up a firewall for an internal network at home mainly to
> keep security inside the network, and to maximize internal network
> speed and file sharing capabilities.
> 
> I want to be able to have the firewall basically transparent using
> ipfiltering so the two computers behind it can still have full access
> to the internet.
> 
> I want to use a 192.168.0.x internal network address.
> 
> The system is a K62 3D with two network cards, a 3com 3c905b, and a
> netgear FA310Tx card. I have access to the internet using the 3com and
> I've gotten the module support for the tulip driver for the other card
> and set up to use the 192.168.0.x network address.
> 
> I use a static IP address setup for eth0 on COX@HOME and run a DNS
> server to be able to lookup names, because I can't get it connected to
> COX any other way without knowing their DNS server addresses. (I lost
> the paper and they don't give them out anymore, they want you to use
> DHCP which incidentally I can't get to work right either)
> 
> Anyways, right about here is where I am confused on what to do next to
> get it to forward packets and masquerade or how to configure it as a
> router of anytype.
> 
> I'm using Slackware 8.0 with a newly compiled 2.4.5 kernel with
> support for NAT, routing and many other options that I knew I needed
> in setup.
> 
> I've read through the many HOWTOs, and other Guides at the LDP
> website, on routing and firewall setup and a lot of it is for Redhat
> which is enough of a difference to confuse me even more.
> 
> Does anyone have any knowledge they could pass me, have a setup like
> this yourself that you could share your experiences, or just have some
> advice for me?
> 
> oh yeah, I have a hub that I was planning on setting up like this:
> 
> Two windows 2000 machines going through a hub, which connects to the
> linux machine through an up port which is connected to the Cable modem
> with the other card.
> 
> I want to be able to share files through the two windows machines, and
> even networked drives, but not with the linux machine at all, just
> those two machines.
> 
> I did not install samba support because since this was the case I
> didn't think it would be needed.
> 
> Ok, where do I start?
> 
> ------------------------------------------------------------------
> J e f f  B a r k e r
> 
> Stickboy Productions
> http://www.stickboyproductions.com
> jeff@stickboyproductions.com
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