In general, SGO licenses on CentOS require a network interface starting with "eth" (typically eth0, but it may change).
First, execute the command: ifconfig
If the network interface name does not start with "eth" then it may fail to work with the license server, and you can follow this procedure to change it.
The most common problem is that the network interface name is not named as ethX. This should never happen with supported configurations (HP workstations with Suse11 or Centos), but it is common in other models, specially laptops.
To change it, the next method substitutes old methods that are now obsolete, and it applies to all systems with CentOS 7.2.
Add the net.ifnames=0 biosdevname=0 options to the linux16 line of the file: /boot/grub2/grub.cfg, and reboot. Now the ifconfig command should show the proper names (eth0, eth1,...).
File: /boot/grub2/grub.cfg
Options: net.ifnames=0 biosdevname=0
Example:
linux16 /boot/vmlinuz-0-rescue-553517d297264295b37afa3187d0a6c6 root=UUID=33133de3-f503-4ca3-aeea-d9132e4e114f ro crashkernel=auto selinux=0 rhgb rdblacklist=nouveau vga=791 net.ifnames=0 biosdevname=0 nosmap
set root='hd0,msdos2' rdblacklist=nouveau vga=791 net.ifnames=0 biosdevname=0
Please note that the important names for the license are the ones appearing with the ifconfig command. It does not matter if OS GUI interfaces use different nomenclatures.
Warning: This procedure should only be used by users with good linux knowledge. Any single mistake on the grub file may render the system unusable.