This has bugged me recently with a customer CentOS server that requires manual ifup of network interfaces following a reboot. Well, thinking about it, it may be that I have to start the network service manually (service network start)....either way. So many solutions to this issue related to not having ONBOOT=yes in the ifcfg file for the interface, but that was not the cause in this instance. I finally discovered the cause today. You can blame the fact that I'm a relative Linux newb to not finding this sooner. Thanks to this forum post for enlightening me (see the answer by b13n1u):
CentOS 6.5 not bringing up network interface automatically after reboot [ifup eth0]
Here's the abridged version of chkconfig --list output from this server:
# chkconfig --list
NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off
network 0:off 1:off 2:off 3:off 4:off 5:off 6:off
So, the services NetworkManager and network are not set to start. So, this should be the solution to the issue. I'm rebooting it this weekend, so I guess we'll see how that works.
chkconfig network on
