[vox-tech] Re: Masquerading

Peter Jay Salzman vox-tech@lists.lugod.org
Thu, 14 Mar 2002 13:48:52 -0800


martyn,

it's been a long while since i've done masquerading by hand (how
embarrasing!) but off the top of my head, do this:

on linux:

point your DNS to your ISP's DNS servers (/etc/resolv.conf)

# bring up the interfaces
ifconfig eth0 external-ip up
ifconfig eth1 192.168.0.1 up
# set up routing
route add default gateway your-ISP-gateway
# set a default policy for the forwarding chain
/sbin/ipchains -P forward DENY
# enable the masquerading
echo "1" > /proc/sys/net/ipv4/ip_forward
# do the masquerading
/sbin/ipchains -A forward -s 192.168.0.2 -j MASQ -i eth0
/sbin/ipchains -A forward -s 192.168.0.3 -j MASQ -i eth0

on windows:
point your DNS at your ISP's DNS servers
use 192.168.0.1 as your gateway.
(i don't use windows, so i don't know how you do this)

i've cc'd vox-tech just in case i screwed up.  i'm sure someone will
correct me in minutes.   :-)

btw, vox-techers, please cc this guy since he's not on the mailing list.

if you use linux, please consider coming to our meetings.
www.lugod.org.  we gladly accept donations to help fund demos,
installfests and our lending library.

pete

begin Martyn R Whittaker <martyn.whittaker@virgin.net> 
> Dear Root,
> 
> I wonder if any of your members would like to do a one or two hours of consulting for me?
> 
> I have set up RedHat Linux 7.2 on my qateway machine at home which contains 2 ethernet cards that seem to be loading up and working fine.  Eth0  is connected to static IP address (ADSL) and Eth1(192.168.0.1) is connected to my home network of 2 Windows PCS (192.168.0.2 and 192.168.0.3)
> 
> I have tried using the Firestarter firewall and also setting up a simple forwarding and masquerading firewall so that I can access the Internet, email etc from my client PCs but without success.  Pinging works fine.
> 
> I suspect someone who knows what they are doing could telnet on to my machine or come round and sort this really quickly.
> 
> I wonder if you could ask your members if anyone would be interested?
> 
> Regards
> 
> Martyn R. Whittaker
> 317 Encina Ave., Davis, CA 95616 USA
> p. +1 530 756 2867  f. +1 253 498 9591  m. +1 916 813 7061