On some newer model Intel NICs they fall asleep at random when using Centos 6.X, or even other OS’s. To combat this, there is a simple addition to the grub.conf that will disable PCIe_ASPM.
At the command line enter:
Once in the grub.conf file, insert this into the end of the kernel line:
Exit, save, and reboot for changes to take effect. To check that changes were indeed made, use the following:
It should return a PCIe Disabled message, confirming the changes were made successfully: