[lug] Win 2 Linux Modem/net pool

[George Sexton]

Here is what you need to do:

1)	Setup a network and make the Linux machine the default gateway. Use a
reserved Address block like 192.168.1.x
2)	Set up a PPP connection using LinuxConf. Test it and make sure it works.
3)	Set the PPP Interface to Activate On Bootup
4)	Add the following PPP Options using LinuxConf: demand idle 600
	These two options enable demand dialling with a 10 minute idle timeout.
5)	Enable IP Masquerading.

A simple script to do this is:

#!/bin/sh
/sbin/insmod ip_masq_cuseeme
/sbin/insmod ip_masq_irc
/sbin/insmod ip_masq_raudio
/sbin/insmod ip_masq_vdolive
/sbin/insmod ip_masq_ftp
#/sbin/insmod ip_masq_quake
echo "1" > /proc/sys/net/ipv4/ip_forward
echo "1" > /proc/sys/net/ipv4/ip_dynaddr

ipchains -M -S 7200 10 60
#
#	Set the default forwarding policy.
#
ipchains -P forward DENY
#
# Disallow AOL Instant Messenger
#
ipchains -A forward -s 192.168.1.0/24 -d 205.188.0.0/16 -j REJECT
ipchains -A forward -s 192.168.1.0/24 -d 198.81.24.0/24 -j REJECT
#
# Enable forwarding for everything else.
#
ipchains -A forward -s 192.168.1.0/24 -j MASQ

You do not need DIALD or any other piece of software. RedHat and PPP will
automatically do this by setting the PPP options. I have a network of 10
machines running with this configuration.

Note that this is a minimal script with virtually no firewalling for the
linux machine. You should carefully secure the machines, and apply all
relevant patches. You may also want to get a book (or two) on Firewalling.
Decent ones would be the O'Reilly firewall book (yellow, I forget the
animal) and the Linux Firewalls book from New Riders Press. If you do not
apply the patches, and crank down the security, you will be hacked. Dead
certainty, 100%.

Good Luck.

George Sexton
MH Software, Inc.
Voice: 303 438 9585
http://www.mhsoftware.com



> -----Original Message-----
> From: lug-admin at lug.boulder.co.us [mailto:lug-admin at lug.boulder.co.us]On
> Behalf Of Gary W Holbrook
> Sent: Thursday, June 15, 2000 12:10 PM
> To: lug at lug.boulder.co.us
> Subject: [lug] Win 2 Linux Modem/net pool
>
>
> Can my Redhat 6.1 Pro version be an internet front end for my
> Win98 boxes at
> my house?  Something like internet connection sharing amongst M$ machines?
> What I would like is when I open my Netscape browser or any other program
> that is looking for the net, that they connect over my ethernet connection
> in the house to the RH machine, which inturn connects over the PSN to my
> ISP.  If it is already connected, my wife is online already, then just use
> that connection.
> Any ideas appreciated.
> TIA,
> G
>
> Gary W Holbrook   Softbrook Corporation   gary at softbrook.com
>
>
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