Unable to activate eth0 under RHEL6

Latest response

Setup a new RHEL6 server and wasn't able to ping other servers on the network.

When running

ifdown eth0 
ifup eth0

ifup eth0 RTNETLINK answers: File exist

I also get the same when running, service network stop and service network start.

Looking under /etc/sysconfig/network-scripts, there was no eth0 file. So I create the file, however I don't have a UUID in it. Also check under /etc/udev/rules.d and the file 70-persistent-net.rules exist too. I've also deleted out /etc/udev/rules.d/70-persistent-net-rules and rebooted along with creating a new eth0 file.

However...

ifup eth0 
Determing if ip address 192.168.122.150 is already in use for device eth0...

However I still cannot ping other servers on the subnet.

I'm wondering what I can do to fix this.

CM
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Responses

SW Red Hat Guru 4017 points
9 November 2015 7:41 AM

Hello

The message RTNETLINK answers: File exists can be displayed because the interface was previously given an IP addresses by DHCP. If you then configure the interface to use static networking, you can see that message. It does not mean the interface is not working. If you cannot ping other servers I suggest checking the interface config file. Please paste it below.

Thank you

SW Red Hat Guru 4017 points
9 November 2015 7:48 AM

The relevant section in the Red Hat Enterprise Linux 6 Deployment Guide is Interface Configuration Files

CM Expert 1105 points
10 November 2015 1:21 AM

This is what my ifcfg-eth0 files looks like:

DEVICE=eth0 
TYPE=ethernet 
UUID= 
ONBOOT=yes
NM_CONTROLLED=yes 
BOOTPROTO=none 
IPADDR=192.168.122.150
PREFIX=24
DEFROUTE=yes 
IPV4_FAILURE_FATAL=yes 
IPV6INIT=no 
NAME=eth0 
HWADDR=08:00:27:86:59:ea
GATEWAY=192.168.122.254

Just to be certain, I also checked under /etc/sysconfig/network and there was no file with eth0 in it as well.

SW Red Hat Guru 4017 points
10 November 2015 8:33 AM

Hello

That looks OK except TYPE=ethernet should be TYPE=Ethernet, or even just omitted as it will default to that. After changing that, try again to ping. If required, confirm neighbors are "up" and in the same subnet.

CM Expert 1105 points
10 November 2015 1:33 AM

I fixed it. This is what I did to fix it. When I ran route -n, there was an entry as the following:

169.254.0.0

I went to /etc/sysconfig/ and vim network and added the following:

NOZEROCONF=yes

Restarted the network and it worked. I also got the solution from here:

http://www.cyberciti.biz/faq/fedora-centos-rhel-linux-disable-zeroconf-route-169-254-0-0/

SW Red Hat Guru 4017 points
10 November 2015 8:31 AM

Hello

Having a route to 169.254.0.0 is not the problem here.

CM Expert 1105 points
11 November 2015 4:20 PM

Ok, I changed that and didn't realize it was case sensitive.

Still seems ok and able to ping other hosts just fine.

CM Expert 1105 points
11 November 2015 4:29 PM

I'm not familiar with 169.254.0.0 under Linux. I know what APIPA is under Windows. This seems to be tied to something called Zero Config.

Looks like a way to stop it is the following:

To disable the zeroconf route during system boot, edit the /etc/sysconfig/network file and add the following NOZEROCONF value to the end of the file:

My /etc/sysconfig/network files has the following:

NOZEROCONF=yes

I can ping all other hosts on the subnet with no issue, also can test nc against various ports too.

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