I just rebooted my CentOS 6.4 box after uncommenting a few lines in NFS configuration after reboot CentOS does not detect the network interface. By running command "service network restart", it says "It seems network interface is not present". Data Center staff says there is no way rather than reloading the OS. I tried deleting /etc/udev/rules.d/70-persistent-net.rules and rebooted. It created the rules file again but it didn't fix.