RH8 as router for win98 box

d33pdream · 03-12-2003, 03:27 AM

REDHAT 8.0 Machine
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eth0 = Internet
eth1 = Internal (goes directly to the windows98 box)

I read up on iptables and understand it's NAT funtions and how to enable it but eth1 PLUS the windows98 machine do not have IP address. Do i need to setup dhcpd to run on that interface? Im a little confused as to how to get that going, it's mannual is rather cryptic (to me).

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Coming off a fresh install of Redhat 8.0 i've done this;

modprobe iptable_nat

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

echo 1 > /proc/sys/net/ipv4/ip_forward

But have a funny funny feeling I need to do something about assigning eth1 an IP and setting it up to release an IP to the other machine.

OR(!) Seeming there is only one other machine on the nextwork (the windows 98 box) can I give 98 and the internal eth1 cards both a class C and tell 98 to use my RH8 eth1 as the gateway? hrm.. don't have access to the 98 box right now but -- would that work? seems like it would

Rickdog · 03-12-2003, 03:51 AM

Check out the diagrams of how the IP addresses are set up in this manual section from Firestarter. It has worked for me dozens of times using NAT. Firestarter, BTW, makes setting up NAT and firewalls ridiculously easy. I never even bother with iptables (mainly cuz it's so friggin complicated) anymore. Firestarter gnome version 2.x.0.9.1 works great with RH 8.0 and I shamelessly plug it all the time.

http://firestarter.sourceforge.net/manual/nat.php

See where the internal device is configured? It says: Default gateway (IP): <leave empty> , it is important to leave the default gateway on the internal device blank, you can thank me for bringing this to their attention. Anyway, it works great and sets up filtering for all sorts of things, Samba included. You can set your IP's with the network device control gui, download firestarter, run the wizard, and have NAT working in about 5-10 minutes. It beats the heck out of banging your head over iptables for days on end.

estranged0877 · 03-13-2003, 07:14 PM

You need to set an internal IP to your internal nic... say 192.168.1.254.

You need to start DHCP and create a dhcp.leases file and create the dhcpd.conf file.

If you need examples let me know and I would be happy to post.

Your internet card just needs to be able to connect to the internet

d33pdream · 03-13-2003, 07:25 PM

Ty for the replies.

Since there is only one machine im connected to (internally) is it really necessary for DHCP? I assigned the internal nice the IP of 192.168.0.1 / 255.255.255.0

And set up the Windows machine to use 192.168.0.1 as it's default gateway.

The windows box is statically assigned 192.168.0.2 / 255.255.255.0

estranged0877 · 03-13-2003, 07:27 PM

did you give the windows machine the ISP's DNS numbers?? How will the windows machine know where to resolve web addresses???

estranged0877 · 03-13-2003, 07:28 PM

so to answer your question, I would assume after putting in DNS info on the windows machine, no you shouldn't need DHCP.

d33pdream · 03-13-2003, 07:30 PM

hrm - Good idea - this i did not think of yet

Where do I obtain DNS info? Can I get such information via netstat on teh RH8 (internet connected) machine?

estranged0877 · 03-13-2003, 07:36 PM

I have always gotten mine from my ISP provider. You can just use common DNS server IP's... for example... before I knew my pacbell dns numbers for my home DSL I used my work ISP DNS numbers and that worked fine.

Where are you getting your DSL/cable internet from - Provider name?

d33pdream · 03-13-2003, 07:42 PM

Thanks -

Im using Roadrunner. So is the person im trying to help that has this problem. I found my DNS info here at home, I'll give her the same addresses. We're not on the same node but im sure it'll work.

Thanks again

d33pdream · 03-13-2003, 07:45 PM

I do recall another problem.

After enabling NAT (via iptables) i tried to ping an IP address from the win98 box and that would not work...

However, I was able to ping the public IP on the RH8 machine...

Dunno. Will find out as soon as i go over there tonight.

estranged0877 · 03-13-2003, 07:52 PM

I just tested it. I am not able to ping the internal IP but I am able to get online with everything done statically with no DHCP enabled. I may not be able to ping the internal IP on RHL8 as I have some stuff enable for security reasons. Although on the RHL I can ping the static windows machine... interesting... sorry I don't know about that one right now.

d33pdream · 03-13-2003, 07:57 PM

Thank you for your help. I'll post my results later tonight.

d33pdream · 03-14-2003, 01:27 AM

k, no go - im ready to freakin' loose it.

fmotta · 03-14-2003, 03:49 AM

You said 'directly into your win98 box' - does that mean that you are not using a router/hub/switch? If you are not using a like device the n you need a crossover cable to do this - it is like a null modem of network cables - this may seem like a sill response - however I have had users make this mistake before.