Author Topic: Configuring 2 Ethernet Cards in RHL 9.0 (Read 24980 times)

ty_young · « **on:** September 08, 2004, 04:35:46 AM »

Currently I setup my linux box to be a transparent proxy w/ firewall (using firestarter and built-in). The box works well with only 1 NIC but things started to go wrong when I installed a 2nd NIC.

Whenever I ping, I couldn't ping to my internal network nor my gateway or whatsoever. Could anybody kind enough to help me out?

ozioma · « **Reply #1 on:** September 08, 2004, 04:46:05 AM »

PLEASE WHICH OF YOUR CARDS IS THE ETH0 AND WHICH IS ETH1

Ricky · « **Reply #2 on:** September 08, 2004, 04:55:36 AM »

first of all you have to assign appropriate ips two both of cards, wether it is from dhcp or static.

Then again run firestart setup ! hope then you will not get any problem.

ty_young · « **Reply #3 on:** September 08, 2004, 05:36:42 AM »

I'm using a static ip address. Eth0 is using 198.1.1.19 (3Com) while Eth1 (Realtek Chip-set) is using 198.1.1.20. I want to connect my Eth0 to my ISP while Eth1 connect to my internal network.

Ricky · « **Reply #4 on:** September 08, 2004, 02:32:50 PM »

and where did you obtained those IP address ? given to you by ur ISP ?

I really don't think that your Eth1 ip should look like that as it is internal network !

ty_young · « **Reply #5 on:** September 09, 2004, 03:39:24 AM »

Ricky, you're right. That was because i was testing it using internal network to simulate a real-world environment. Earlier I put my Linux box for test in the following configuration:

Eth0 IP: 202.179.113.124
Mask: 255.255.255.248
Gateway: 202.179.113.121

Eth1 IP: 198.1.1.18
Mask: 255.255.255.0
Gateway: 198.1.1.18

I tried to Ping both internal and external IP but to no avail. Any suggestion?

Ricky · « **Reply #6 on:** September 09, 2004, 04:17:06 AM »

NOw I think I am confused.. I am really unable to understand that wht you want to do ?

Well in the case you want to connect to your ISP and if your ISP provides you static IPs then simply assign that IP to your ethernet and other info.. like DNS , like gateway.

In your internal network card you don't need to assign gateway if that machine is directly connected to internet , other clients will require the gateway as of your LAN NIC ip .

hmm.. may be you can understand wht I am saying.. but make sure to check ur firewall rules.. they are mostly to block pinging..

ty_young · « **Reply #7 on:** September 09, 2004, 04:39:43 AM »

Sorry for the confusion. I'll try to clarify my situation. Now I have deployed my Linux Box into test using my ISP given fixed ip which I specified earlier and the 2nd NIC is connected to my internal network. anyway, i'll try you method and see how it goes. Thanks.

ty_young · « **Reply #8 on:** September 10, 2004, 03:12:59 AM »

I've been trying for hours trying to get both my NICs working right but so far to no avail. Whenever i try switch the setting between two cards, for example Eth0 is set to as Gateway while Eth1 is set to internal network, Eth0 would ping succesfully but not Eth1. If I try to switch the setting again, I could ping external successfully but not internally. For you information, I tested my both NICs and they work flawlessly. Can anybody show me show clue on what's going on?

By the way, Eth0 is using SMC2-1211TX while Eth1 is using 3c905-TX/TX-M (Tornado). At this moment my setting is as below:

Eth0: 198.1.1.10 (Static IP)
Mask: 255.255.255.0
Gateway: -

Eth1: 202.179.113.124
Mask:255.255.255.248
Gateway: 202.179.113.121 (ISP Static IP)

In this case, I can ping my internal network but not my external network.

Ricky · « **Reply #9 on:** September 10, 2004, 06:37:19 AM »

HI..

there is notthing which you can decide from pinging on same machine.. ie sometimes etxternat and sometimes internalk

Well forget all l..

NOw

When y ou get a connection from an ISP then you should be given at 3 things..

a. your NODE Ip address
b. subnemt mask (usually 255.2555.255.0) or depends upon ur ISP.
c. DNS servers

So if you you are provided with above settings then in your external NIC put Ip address, dns, and subnet and in gateway give same as your IP.
and if they provide you separate gateway then provide gateway also as given by them.

Now for your LAN

First of all enable routing on your machine which is directly connected to internet ie the one with two NIC.

Now give Ip as you wish..
say I am gving 90.0.0.1 / 255.255.255.0 , leave gateway blank as gateway is already specified on extrnal nic.

Now your clients who are connected to your machine through LAN NIC .. in those specifiy ip as 90.0.0.2 and subnet as 255.255.255.0 and gateway at 90.0.0.1 , and dns as your ISP's dns..

HOpe you will get it solved now !

ty_young · « **Reply #10 on:** September 10, 2004, 08:30:01 AM »

I think I'VE FOUND OUT THE COURSE OF MY PROBLEM NOW. The Hardware section in the Network configuration mess up my NICs , big time! I've set my Eth0 as Tornado while the Eth1 as SMC. when i set my devices, the system cross switch both NICs! Eth0 to SMC while Eth1 to Tornado! eventhough i double check my hardware setting is right! I wonder what course of this? But i'll try to fix the problem and sees how it goes from there.

ty_young · « **Reply #11 on:** September 10, 2004, 02:41:04 PM »

I tried to remove my NICs and delete all the configuration and start a fresh installation. this time the setting is nice and match. I set my Eth0 (SMC) as a gateway to my ISP while my Eth1 (3com) serves as my internal network.

But later to my dismay, the same problem happens again. the difference is, this time i can ping my external ip but not internally..... and quite interesting I setup another pc to ping my linux box, i was able to ping the internal network just once... Anyone got a clue what's going on?

ty_young · « **Reply #12 on:** September 13, 2004, 01:37:04 AM »

Ricky, Could you be a bit specific about the 'enable routing' part.I'm would like to know about that part in more details. For now, I'm using the network configuration's GUI, to set my routing but i'm not quite sure am I doing it right.

For example, For my Eth0 (Tornado) in which connecting to ISP, I add an entry : Destination Network: 198.1.1.19, mask 255.255.255.0 into Network Static Route. on the other hand, Eth1 (SMC) connecting to internal network, Destination network: 202.179.113.121, mask 255.255.255.248. Is it correct? Thanks.

Ricky · « **Reply #13 on:** September 13, 2004, 05:18:12 PM »

I am talking about NAT .. see Tutorial section to do that ! btw you have asked ur same problem at another place.. was that necessary to ask there ?

ty_young · « **Reply #14 on:** September 14, 2004, 01:13:12 AM »

I've already went thru the tutorial earlier and it works fine for me. By the way, about the other forum I posted earlier, well I thought it is a separate problem so I just do it. If it's causing problem, I won't mind to stop it. thanks.[/quote]