Hi. I'm trying to get IP Masquerade set up. I've been following the guide at:
tldp.org/HOWTO/IP-Masquerade-HOWTO/ and I'm trying to use his example rc.firewall-2.4 file

eth0 is my cable modem, and eth1 is the nic for the internal network.
eth0 works fine, I have internet on the host machine.
eth1 is giving me difficulty. If I type "ifconfig eth1 192.168.0.1 netmask 255.255.255.0 up"
I can force it to take an IP and allow me to ping it from the client machines, but I can't get 192.168.0.1 to stick to eth1 through a boot if I'm also running the rc.firewall-2.4 file from the howto.

I'm sure there's a really easy answer to this, but I'm not seeing it.

Once I boot with rc.firewall-2.4 and force it to accept 192.168.0.1 by typing "ifconfig eth1 192.168.0.1 netmask 255.255.255.0 up", ifconfig -a looks like this:

eth0 Link encap:Ethernet HWaddr 00:01:02:60:22:AC
inet addr: My ip from my isp Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4589 errors:0 dropped:0 overruns:0 frame:0
TX packets:5365 errors:0 dropped:0 overruns:0 carrier:0
collisions:134 txqueuelen:100
RX bytes:1805784 (1.7 Mb) TX bytes:3665058 (3.4 Mb)
Interrupt:11 Base address:0xcc00

eth1 Link encap:Ethernet HWaddr 00:01:02:24:22:B5
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3056 errors:0 dropped:0 overruns:0 frame:0
TX packets:1607 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:3281147 (3.1 Mb) TX bytes:122636 (119.7 Kb)
Interrupt:10 Base address:0xd000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:24 errors:0 dropped:0 overruns:0 frame:0
TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1680 (1.6 Kb) TX bytes:1680 (1.6 Kb)

if I don't force it to take 192.168.0.1 it doesn't have an IP at all. How can I make it stick?

check
/etc/sysconfig/network-scripts/ifcfg-eth1
IPADDR="192.168.0.1"
NETMASK="255.255.255.0"
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
ONBOOT="yes"

Hi GentleMuffin

Which distribution do u use ???

If you're on Woody, I'd really appreciate your telling me how you set up your DHCP client with the cable modem.

Thnx in advance

iraysyvalo, using Slackware 9.0, and I didn't have to do a damn thing to set up the cable modem. I installed slackware and it just kinda worked :-P

I figured it out, /etc/sysconfig/network-scripts/ifcfg-eth1 doesn't exist on my machine, but I went into /etc/rc.d/rc.inet1 and was able to assign 192.168.0.1 to eth1 easily. I feel like an idiot.

That's done. But I still can't get sharing to work. As it is now my ifconfig -a looks like this:

eth0 Link encap:Ethernet HWaddr 00:01:02:60:22:AC
inet addr:My IP from my ISP Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:204 errors:0 dropped:0 overruns:0 frame:0
TX packets:300 errors:0 dropped:0 overruns:0 carrier:0
collisions:1 txqueuelen:100
RX bytes:75558 (73.7 Kb) TX bytes:212388 (207.4 Kb)
Interrupt:11 Base address:0xcc00

eth1 Link encap:Ethernet HWaddr 00:01:02:24:22:B5
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:297 errors:0 dropped:0 overruns:0 frame:0
TX packets:165 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:202584 (197.8 Kb) TX bytes:21765 (21.2 Kb)
Interrupt:10 Base address:0xd000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:400 (400.0 b) TX bytes:400 (400.0 b)

I get this at boot, without forcing it to take the IP manually, but sharing still doesn't work.

I'm using this rc.firewall-2.4 file, http://www.tldp.org/HOWTO/IP-Masquer...-examples.html