Redirect two different networks wlan0/eth0

Elie Dac · 05-28-2013, 07:39 AM

Hi all,

I am really a newbie, so this can look like a basic question, however I still have not found the answer googling it.

I can access two different networks:
* One from my company using eth0
* Another one in wifi using wlan0

The main idea is to be able to correctly use both interfaces at the same time.
Because with the eth0 interface, I cannot access the network outside my company, and with wlan0 I cannot access the network inside my company

So I want to be able to access some domains in both networks.

Usually, I connect wlan0 using the network manager:

Code:

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.46  netmask 255.255.255.0  broadcast 192.168.1.255

Then, I manually set a static IP for eth0:

Code:

sudo ifconfig eth0 10.45.121.21 netmask 255.255.254.0 broadcast 10.45.121.255

Now, my route table:

Code:

sudo ip route

default via 192.168.1.1 dev wlan0  proto static
10.45.120.0/23 dev eth0  proto kernel  scope link  src 10.45.121.21
192.168.1.0/24 dev wlan0  proto kernel  scope link  src 192.168.1.46

Because, all IP adresses on my company starts with 10.*, I replace the current gateway (it may be a bad idea):

Code:

sudo ip route del 10.45.120.0/23
sudo ip route add 10.0.0.0/8 dev eth0  proto kernel  scope link  src 10.45.121.21

So my route table looks like this:

Code:

sudo ip route

default via 192.168.1.1 dev wlan0  proto static
10.0.0.0/8 dev eth0  proto kernel  scope link  src 10.45.121.21
192.168.1.0/24 dev wlan0  proto kernel  scope link  src 192.168.1.46

Finally my /etc/resolv.conf:

Code:

# Generated by NetworkManager
nameserver 192.168.1.1

This way, I can ping IP addresses that begin with 10.*.
I can also ping google.com.
But as my resolv.conf suggests, I am not able to ping a domain on the 'eth0' network, so this is kind of annoying.
I already know that if I set eth0 as the default network using the Network manager, the resolv.conf is:

Code:

# Generated by NetworkManager
nameserver 10.45.20.3

So I was hoping that maybe someone had a better idea setting the two networks together more easily

MikeDeltaBrown · 05-30-2013, 06:12 PM

I'm not familiar with NetworkManager but there must be a way to add another 'nameserver' line. You'll need to put 192.168.1.1 back into the file.
<checking>...
Looks like you add these lines to the relevant interface file:
In ifcfg-wlan0 add:
DNS1=192.168.1.1
and in ifcfg-eth0 add:
DNS1=10.45.20.3

This from: https://live.gnome.org/NetworkManager/SystemSettings under Nameserver section about half way down.