[SOLVED] Without NetworkManager, how to keep the DNS info for both NICs ?

5883 · 01-12-2012, 04:15 PM

say i don't have NetworkManager in the embedded linux,
all i have is /etc/resolv.conf for DNS, if i understand this correctly.

Now i have 2 NICs may connect to 2 different networks,
can i save the DNS info separately ?

Many thanks !

T3RM1NVT0R · 01-12-2012, 04:46 PM

Hi 5883,

You can specify the DNS in your network interface configuration file. You can specify DNS using following param:

DNS1=xxx.xxx.xxx.xxx
DNS2=xxx.xxx.xxx.xxx

Just make sure PEERDNS is set to NO otherwise it will update resolv.conf file with this information.

5883 · 01-12-2012, 05:53 PM

wow, do you have a sample link somewhere ?
i did google and didn't find any samples.
thanks !

Quote:

Originally Posted by T3RM1NVT0R

Hi 5883,

You can specify the DNS in your network interface configuration file. You can specify DNS using following param:

DNS1=xxx.xxx.xxx.xxx
DNS2=xxx.xxx.xxx.xxx

Just make sure PEERDNS is set to NO otherwise it will update resolv.conf file with this information.

T3RM1NVT0R · 01-13-2012, 12:27 AM

You're welcome!

Here is the sample link: http://www.mombu.com/gnu_linux/mandr...f-1508104.html

5883 · 01-13-2012, 12:25 PM

well, not sure i get it right, this is ubuntu, kernel 2.6.32

===== my /etc/network/interfaces =====
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

auto eth1
iface eth1 inet static
address 4.5.182.182
netmask 255.255.252.0
gateway 4.50.183.254
dns-nameservers 4.2.8.9

After reboot, my /etc/resolv.comf is still
nameserver 10.38.78.5
nameserver 10.38.58.5
domain thiscompany.ad
search thiscompany.ad

i'm not seeing my 4.2.8.9,

T3RM1NVT0R · 01-13-2012, 12:32 PM

If you want the NIC files to update resolve.conf then put the following entry in NIC:

PEERDNS=yes
DNS1=xxx.xxx.xxx.xxx

and then it should update your resolv.conf file.

Make sure that you take a backup of the files before editing.

5883 · 01-13-2012, 06:37 PM

T3,

what is "NIC files" ?
i'm using ubuntu, never seen things like "PEERDNS, DNS1=..."

thanks !

Quote:

Originally Posted by T3RM1NVT0R

If you want the NIC files to update resolve.conf then put the following entry in NIC:

PEERDNS=yes
DNS1=xxx.xxx.xxx.xxx

and then it should update your resolv.conf file.

Make sure that you take a backup of the files before editing.

T3RM1NVT0R · 01-14-2012, 06:29 AM

Alright so you are using Ubuntu. That clear up the things a bit. I have checked this on my Ubuntu 11.04 system and here is the location where you should look for:

Quote:

/etc/NetworkManager/system-connections

Under this you will find out the connection files for your Wired Connection as well as Wireless Connection. I am using wired connection so I have got a file with the name Wired Connection 1. When I did a cat on this file here is the output that I got:

Code:

[802-3-ethernet]
duplex=full
mac-address=xx:xx:xx:xx:xx:xx

[connection]
id=Wired connection 1
uuid=0acd594e-89a1-402a-9610-deecb10e766e
type=802-3-ethernet
timestamp=3548542633

[ipv6]
method=auto

[ipv4]
method=manual
dns=192.168.1.1;
addresses1=192.168.1.20;24;192.168.1.1;

I will explain the [ipv4] section as that is the section where you need to edit the stuff. method=manual it means I have statically setup my ip address. dns=192.168.1.1 is my dns server which this interface will going to use. addresses1=192.168.1.20 is the IP I have configured on this machine. 24 is the subnet mask in use. 192.168.1.1 is also acting as my default gateway.

Make sure you take backup of any configuration file before making any changes to it. It is good to be safe then sorry :-)

5883 · 01-14-2012, 09:40 AM

T3, 1st of all thanks very much for spending time looking into this.

i looked at networkManager before, but there's 1 issue blocking me from using it.
For our app, we have to make network changes in the command line, meaning we have to manually
edit the "Auto eth0", "Auto eth1" files under the /etc/NetworkManager folder.

But if you do a fresh install of ubuntu, i don't see these files,
until i click the up/down arrow icon in the right corner of the desktop, that's to bring down/up the network.

So for me, since i cannot access the desktop, i need to manually generate the "Auto eth0".
Then i can edit the ip address etc.

But there's a "uuid" field, i did't know where to get it. So i stopped there.

Our app will be running in the embedded board, that's why i have to use command line.

Quote:

Originally Posted by T3RM1NVT0R

Alright so you are using Ubuntu. That clear up the things a bit. I have checked this on my Ubuntu 11.04 system and here is the location where you should look for:

Under this you will find out the connection files for your Wired Connection as well as Wireless Connection. I am using wired connection so I have got a file with the name Wired Connection 1. When I did a cat on this file here is the output that I got:

Code:

[802-3-ethernet]
duplex=full
mac-address=xx:xx:xx:xx:xx:xx

[connection]
id=Wired connection 1
uuid=0acd594e-89a1-402a-9610-deecb10e766e
type=802-3-ethernet
timestamp=3548542633

[ipv6]
method=auto

[ipv4]
method=manual
dns=192.168.1.1;
addresses1=192.168.1.20;24;192.168.1.1;

I will explain the [ipv4] section as that is the section where you need to edit the stuff. method=manual it means I have statically setup my ip address. dns=192.168.1.1 is my dns server which this interface will going to use. addresses1=192.168.1.20 is the IP I have configured on this machine. 24 is the subnet mask in use. 192.168.1.1 is also acting as my default gateway.

Make sure you take backup of any configuration file before making any changes to it. It is good to be safe then sorry :-)

T3RM1NVT0R · 01-14-2012, 10:03 AM

To get the UUID you need to find out the device file attached with your ethernet device. And then you can run the following command to get the UUID:

Code:

blkid <device_file>

5883 · 01-14-2012, 10:50 AM

Excellent，thanks again !

Quote:

Originally Posted by T3RM1NVT0R

To get the UUID you need to find out the device file attached with your ethernet device. And then you can run the following command to get the UUID:

Code:

blkid <device_file>

T3RM1NVT0R · 01-14-2012, 10:51 AM

You're welcome. Please mark the thread as solved.

Enjoy linux!!!