iptables Firewall for typical home users

mymojo · 12-15-2003, 09:26 AM

thank you JordanH! you're my hero!

Xenocide · 12-16-2003, 08:48 AM

Quote:

Originally posted by JordanH
Firstly, IANA has set aside specific ip address ranges for private use. 90.0.0.0/8 is not one of them. That particular network is reserved and although you *can* use that as your network, it is not a good idea.

Secondly, I can't think of a way to use Linux as a hub. As I see them, your options are hub/switch -or- separate your network into subnets. The hub/switch solution is best, however, for the $0 budget, you can split it into two subnets.

Lastly... SMB... To tell you the truth, I don't know. I suspect you should be able to share your files just fine however, I'm not the person to ask on this subject althought I would put my money on it.

Tell you how to config your network? ok.
Linux machine
eth0 192.168.0.1/24
eth1 192.168.1.1/24
Ensure routing table sends traffic to the correct cards
Ensure your iptables firewall allows forwarding between internal NICS

Machine 1
eth0 192.168.0.2/24
gateway: 192.168.0.1

Machine 2
eth0 192.168.1.2/24
gateway: 192.168.1.1

right thankyou ill change that at some point lol.

eth1 isnt working atm (card's fooked) so its not urgent but that sound v good thanks.

When u say x.x.x.x/yy what does the yy mean?

JordanH · 12-16-2003, 09:12 AM

So many good questions in one thread. We should have really broken this one up.

The /yy part is the network mask. It defines the network as opposed to just one address. Check out this link for a good discussion on the subject:
http://www.linuxquestions.org/questi...hreadid=123068
Post there if you have more questions and I will follow-up with you.
Regards,
J.

trinhnamthai · 12-17-2003, 01:59 AM

Hello , Please help me how to share internet connection (ADSL)on Linux 9.0 for LAN ussing windows 2000. I have ADSL modem use USB.

Many thank.

Thai

JordanH · 12-17-2003, 07:37 AM

Hi Trinhnamthai...

You should post your questions in a new thread.

Here are the steps in short - follow them in order.
1. Setup your USB modem... sorry, I have no experience here.
2. Configure your ethernet cards. If you have trouble, ask in the Networking forum.
3. Setup your Firewall. The above script will let you share your ADSL connection with your LAN.
4. Setup your client machines to use your Linux machine as the "Default Gateway".

Again... your questions are good but please post them in a NEW thread.
Regards.

Xenocide · 12-29-2003, 05:01 PM

I got myself a switch like you suggested and now there are 5pc's all on this one connections. Thankyou Very much again. Without ne mods it works. Bulletproof ^_^

Jakerohs · 12-29-2003, 09:41 PM

Thanks so much! Very useful script

Works like a charm.

mikedeatworld · 02-05-2004, 01:04 PM

Jordan-

Why are the two nic's looking at different gateways?

And not just 192.168.0.1?

thanks

Mike D

JordanH · 02-05-2004, 01:51 PM

Hi Mike,
I'm a little confused by your question, perhaps you can give me more details about what you want to know.

The firewall script above does not specify anything about gateways so perhaps that isn't the term you meant to use. If you are talking about Internet gateways, that is a function of your routing table... you can use the route command to show to which gateways your NICs are pointing.
In my case, I only have one gateway specified and it is assigned to my ppp0 adapter (the default route). This is the other end of the ppp connection to which I need to route traffic. My ethX NICs do not have an associated gateway.

Try your question again and I'll see if I can answer it more clearly.

uvone · 04-03-2004, 11:25 PM

hey
looking for a good iptables firewall script for a dial-up connection, from what peoplehave said this is good but will it work with dial-up??

JordanH · 04-04-2004, 01:11 AM

It should work just fine with dial-up. Dial-up is pretty much the same as ADSL so your external interface will be ppp0 instead of say eth0. Make sure you change the ext and int variables to your external interface (ppp0) and internal interface eth?

let us know if you have any problems.
J.