What is a UUID? How to generate and Set UUID for NICs and Bonds on RHEL/CentOS

What is a UUID?

A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems.
How to generate and Set UUID for NICs and Bonds on RHEL/CentOS

When you work with the Network management tools like nmcli or nmtui they create it automatically and save it in the config file. While you create the configurations manually, you'll need to generate the UUID for NICs or bonds. Let's do that now.


1. For Example, Lets Generate UUID for em1 interface through uuidgen .
[root@DBBACKSERVER ~]# uuidgen em1
e9932709-4717-486f-a9a8-a8b8d89ed017
2. Now add the UUID value to to em1 Configuration File.
[root@DBBACKSERVER ~]#vi /etc/sysconfig/network-scripts/ifcfg-em1
UUID=e9932709-4717-486f-a9a8-a8b8d89ed017
3. Now save the Config File
4. Restart the Network Service to take that effect.
[root@DBBACKSERVER ~]#systemctl restart network

You can Generate UUID for Bond Network as well. Lets Do that:
[root@DBBACKSERVER ~]# uuidgen ifcfg-bond0
9e0ca102-1bf8-4789-bcf3-38e8bafaf1af
1. Now add the the UUID to Bond0 Config File.
[root@DBBACKSERVER ~]# vi /etc/sysconfig/network-scripts/ifcfg-bond0
2. Restart the Network Service to take that effect.
3. Now you can Check the UUID's for this device is Properly Set or Not.
[root@DBBACKSERVER ~]# nmcli connection
NAME         UUID                                  TYPE            DEVICE
bond0        9e0ca102-1bf8-4789-bcf3-38e8bafaf1af  bond            bond0
em1          e9932709-4717-486f-a9a8-a8b8d89ed017  802-3-ethernet  em1
em2          b11498f4-cc61-4366-a7bd-cec968be9e42  802-3-ethernet  em2
[root@DBBACKSERVER ~]#