noob needs help

[capo]

So i have moved to colledge and am now studying IT and electrical engineering so i though i should finaly swap over to linux all the way. My current set up is:

1st computer->
200gb HD, athlon 2600+ 512mb of ram, 9600XT,
Running fedora core 4
This machine is connectted to the DHCP server @ the colledge and has been sucesfully assigned an IP etc. and can acess the DNS server and the internet. I am posting from it atm however i do not plan to use this PC as my main one, this pc is gonna be used to hosts various services that i desire, such as HTTP, samba, direct connect etc. This computer is extremely quiet and when underclocked to 1250mhz consumes very little power aswell and is hence left on 24/7 running these servers. I have alreadys et up the direct connect and http and got that working over the colledge network (no previous filesharing infostructure.) And i am now ready to set up PC no.2

2nd computer->
opteron 165 @ 2.6ghz, asus A8n32-SLI delux, 7800GTX, 2gb of OCZ platnium EB pc4000 3 * 160gb baracuda HD, custom watercooling etc.
This is my beast but it consumes alot of power and is very loud so it will only be on wehn i am using it, hence hosting all my files and services on the other pc. So i just grab my switch, and hook this one up to the wall aswell right? WRONG!!!

PROBLEM: i am only allowed one MAC adress and one IP adress:

Solution: Only connect my 'linux box server' to the colledge network then use my second network card to connect that computer to my beast, then use NAT to connect the beast to the colledge network.

Sounds like a plan: So far i have installed the second netowork adapter in my 'linux box' and got it working (i was suprised i mangied that, had to config /etc/sysconfig/network-scripts and everything!) So I set the ip of my second adapter manualy, to 192..168.1.1 Then i jumped over to my beast which is currently running windows and set the ip of one of it's network adapters to 192.168.1.2 and pinged my 'linux box', All ok, i even connected to the DC hub on the 'linux box' and used the DC client on my linux box to backup all my files on my beast. But now i come to the questions part:

How the hell do i share my internet connection to my second computer? I have read all about ip chains and ip tables and ip masquerading and i am only getting more and more confused. Can anyone link me to some sort of definitive guide with all the steps i need to take? or explain how themselves?

And what about the DNS, how do i find out the DNS server my linux box is connecting to (it was assigned automaticaly by the DHCP server) and can i use this DNS on my beast or will that not work because it will not be able to connect to it directly (behind linux-box) and hence i may have to hosts my own DNS on the linux box??

And also what about the OS on my beast, will i need 2 configs on my linux-box, one for sharing internet with windows and one with linux. And i also have questions about setting up dual boot on my beast. I want to run a raid5 but it doesn't work properaly if i use my fakeraid (nforce 4) even though i can isntall windows on it the bootloader seems to fail on a raid5. And what about FC4? Can FC4 be isntalled on a fakeraid? Should i jsut ditch windows and use disk druid to set up a raid? Can disk druid set up a raid 5? Would grub fix the problems i was having with the windows boot loader + fake-raid5?

man thats a lot of questions
Thx in advance, Chris.

[urzasrage]

FYI, from what I have heard, most schools will not allow you to set up your own network, hence the one ip address.

[capo]

already cleared it with the sys admin. And it's not a school.

[w5set]

Buy a cheapo broadband router and use MAC cloning.
Check the box first to make sure it will do MAC cloning before buying.

[capo]

but i already have all the hardware i need. I jsut have to configure the NAT on my linux box

[w5set]

Ok--install firestarter.
it'll allow inet connection sharing and other stuff too.
But even then you are going to have to fix the 2 MAC's problem.
I'm not sure if it (firestarter) spoofs/clones the MAC or not. ??

[pewterdragn]

Sounds like you've done great on your own so far. You are off to a good start.

For connection sharing you will be using the first computer as a firewall/gateway using IP FORWARDING. Here is a good HOW-TO from linux.com:

http://www.linux.com/howtos/IP-Masquerade-HOWTO/firewall-examples.shtml

You will also want to make sure you've installed the caching name server and configured it so that "beast" can ask the "server" for DNS requests:

http://www.linux.com/howtos/DNS-HOWTO-3.shtml
You could also install a DHCP server on "beast" so that you don't have to worry about configuring your windows machine.

As for the dual booting there are a million posts on this site I'll let you search for with this advice:

1) Never try to install on fakeraid - it isnt worth it and linux software raid is as fast or faster.
2) Your /boot partition can not be RAID5: You can use 1 or 0 (recommend 1)

Another thing you can do is use FIREWALL BUILDER for a full GUI of your IPTABLES including managing your MASQUERADING: http://www.fwbuilder.org/
I could be wrong because I haven't used it in ages but I think FIRESTARTER is more of a personal firewall tool. For all intents and purposes you are building your own Firewall/Router device.

Make sure that your external ports are closed down nicely!

[capo]

There is no 2 mac problem:

I only conect to the colledge network with the linux box on the first network adapter (192.168.1.XXX)
then i have my own private network withing my room which the linux box conects to on the second adapter (192.168.1.XXX)
This way only 1 mac adress is actualy connected to the colledge network and the other computer gets the internet via the linux box, hence the NAT. Ill look up firestarter.

[capo]

Ok i installed a dhcp server on the 'linux-box' and then used firestarter to configure the NAT, and it's all working. Beast was assigend an IP and can connect not only to the severs on 'linux-box' but also to the net, DNS and all :)

[pewterdragn]

Ok i installed a dhcp server on the 'linux-box' and then used firestarter to configure the NAT, and it's all working. Beast was assigend an IP and can connect not only to the severs on 'linux-box' but also to the net, DNS and all :)

Good Job and Congrats!