CentOS 6 crashed after restarting network

One of our dedicated servers, which is CentOS 6 based crashed today after I wanted to restart the network interface. Simply after running the following command

service network restart

The box has crashed and I had to reboot it. After server comes up, I have checked the logs to see what was wrong on the server. I have found it.

There is a new and current bug which might be solved on CentOS 7, but not yet on CentOS 6. The bug is in “ifdown-eth” script on CentOS which looks like following :

if [ -d "/sys/class/net/${REALDEVICE}" ]; then
 if [ "${REALDEVICE}" = "${DEVICE}" ]; then
 ip addr flush dev ${REALDEVICE} scope global 2>/dev/null
 else
  ip addr flush dev ${REALDEVICE} label ${DEVICE} scope global 2>/dev/null
 fi
[...]

The issue is in the loop-back interface, so we have to change the script to something like following:

if [ -d "/sys/class/net/${REALDEVICE}" ]; then
 if [ "${REALDEVICE}" = "lo" ]; then
  SCOPE="host"
 else
  SCOPE="global"
 fi

 if [ "${REALDEVICE}" = "${DEVICE}" ]; then
  ip addr flush dev ${REALDEVICE} scope ${SCOPE} 2>/dev/null
 else
  ip addr flush dev ${REALDEVICE} label ${DEVICE} scope ${SCOPE} 2>/dev/null
 fi
[...]

After changing the script and restarting the interface, the server was working fine again.

I hope this can help you all, who faces the same issue.