This is thought to be a very simple network problem. I want to set a network with my home mate's windows XP. Shortly there are two computers connected to each other directly by an ethernet cable. There isn't an hub. We want to share our files and internet. We will be having a cable internet connection in few days, so we want all things to be set by that day. My computer will be the gateway. Yesterday, we tried to set a local network at home. Red Hat 9.0 recognised my ethernet card properly. In fact I don't know what to do now?
I am brand new on this subject. I even don't know what information is needed for someone to answer this !

Things you need:

1 CROSS-OVER ethernet cable (for the computer->computer connection)

2 (total) network cards in the gateway (1 for the internet service, 1 for the compter-to-computer connection)


you'll need to set ip addresses for both computers:

if eth0 is used to connected to the internet, leave it alone for now.

assuming eth1 is connected to the windows XP machine, do this:

(as root users)
open the file /etc/sysctl.conf and modify the line that says
to
also, as root do this(to avoid having to reboot)

as root again
that last part you'll want to put in a script that runs everytime you boot up. also, this setup is very NOT SECURE. Because you are new, i didnt go into the whole firewalling thing but you will want to learn iptables ASAP (like before you get the internet connection).

there are several threads on LQ (this site) about itables. try doing a search (4th blue button on the second row at the top, right-hand side of the screen). You should find a wealth of good examples. Also, here is a link to a howto taht i just "googled" for:

http://www.netfilter.org/unreliable-....linuxdoc.html


oh i almost forgot, you'll have to setup the windows machine:

1. give it an ip address of 192.168.0.X where X is anything except for 0, 1 or 255.

2. give it a netmask of 255.255.255.0

3. give it a gateway/default router of 192.168.0.1 (the linux box)

4. DNS servers will be whatever you get from you internet service provider.

the setup for win XP is located in Control Panel -> Network Connections.

RIGHT mouse click on the Local Area Connection icon
Click Properties
Highligh the line that say Internet Protocol (TCP/IP)
then Click the Properties button

you'll see a screen where you can enter in all that information.

to check that you have the right info entered in:

Click Start -> Run type "cmd" (without the quotes) and hit enter.

When you get teh command prompt type the command:
ipconfig /all

and you should see the information you entered.

if i left something out, someone please correct me, its almost 4am and im a little sleepy.

Thanks for your help Robert0380, you have been very very very very helpfull

Next I have other questions,

Robert0380 said

(total) network cards in the gateway (1 for the internet service, 1 for the compter-to-computer connection)

1) I have one network card, and that is for computer-to-computer connection. Will I need to buy one more for the cable connection, I think there will a modem given by the service provider. I mean I didn't need a network card for the dial-up connection at least, the communication was via serial port . Anyways I guess this wasn't a LQ problem

2) Robert0380 as I said you helped alot, but I will do what you wrote but I want to learn what I am doing by those commands, can you or someone else explain me what these do.


i) #ifconfig eth1 192.168.0.1 bcast 192.168.0.255 netmask 255.255.255.0

ii) open the file /etc/sysctl.conf and modify the line that says

code:--------------------------------------------------------------------------------
net.ipv4.ip_forward = 0
--------------------------------------------------------------------------------

to

code:--------------------------------------------------------------------------------
net.ipv4.ip_forward = 1
--------------------------------------------------------------------------------



iii) also, as root do this(to avoid having to reboot)

code:--------------------------------------------------------------------------------
#echo 1 > /proc/sys/net/ipv4/ip_forward
--------------------------------------------------------------------------------

iv)as root again

code:--------------------------------------------------------------------------------
#iptables -P FORWARD ACCEPT
#iptables -A POSTROUTING -t nat -s 192.168.0.1/24 -j MASQUERADE
--------------------------------------------------------------------------------


that last part you'll want to put in a script that runs everytime you boot up. also, this setup is very NOT SECURE. Because you are new, i didnt go into the whole firewalling thing but you will want to learn iptables ASAP (like before you get the internet connection).

windows part is my home mates problem he should have used Linux also

Usually the cable modem will connect via ethernet, hence needing a second ethernet card, though the one I have can also connect via USB.

i will try to explain each stmt one by one
1) ifconfig is used to configure ur ethernet card(s), if u r using 2 ethernet cards and first one is reserved for net conn, then u have to configure 2nd card for ur local network(in ur case u have 2 m/c), so using ifconfig u r just configuring
a) ip address(192.168.0.1 in ur case)
b)broadcast add
c)subnet mask (255.255.255.0 generally used for C-class network)

2) /etc/sysctl.conf entry enables ur machine to communicate(forward ) ip packets to other machine. this sol is only for Redhat user in my opinion
3)doing the same thing as first but here u need not reboot the machine
4)ipchains allows u to configure firewall. u can read How-tos to understand all these concepts