I have an unmanaged dedicated server that I administer, running CentOS. Recently when I reboot the server, I am unable to use SSH. Both times this has happened the server host has determined the issue and explained it like this:
"Please check now - I'm not sure how and why but eth0 and eth1 were both active on boot (there should only be one). I've fixed this and rebooted the server which came up cleanly with network connectivity. If you have any application that could be making this change, kindly disable the same as well."
So in order for me to check into this myself, I am wondering where to look in order to see the settings he is describing there? That way I can configure it myself and try and determine if any programs are changing this.
Note: I have been using the 'reboot' command, could this be resetting the ONBOOT status?