[CentOS] UUID for network cards

Thu Dec 15 13:23:34 UTC 2011
Dennis Jacobfeuerborn <dennisml at conversis.de>

On 12/14/2011 04:47 PM, Helmut Drodofsky wrote:
> Hello,
>
> with CentOS 6, my new server created an UUID entry in ifcfg-eth0 -
> additional to HWADDR entry.
>
> Up to CentOS 5 the connection to the netwark card was defind only by HWADDR.
>
> Now I have a new network card. How can I get the correct UUID?
>
> The server connects correct the network with the updated HWADDR without
> any UUID. Why do I need an UUID?
>
> Thank you for help in advance.

I'm only speculating here since I did notice the new UUIDs but haven't had 
to deal with them so far but my guess is that they provide a way for the to 
uniquely identify the logical interface and have nothing to do with the 
phyiscal interface itself. For example if you configure bridging you need 
to tell the interface the bridge they belong to. If you use the name "br0" 
for example and later decide to rename it to "bridge0" then you also have 
to fix all references. If instead you reference the UUID then that is not 
necessary and you can rename them as you please without breaking any 
references.

Again this is speculation on my part based on how/why the UUIDs for disks 
where introduced.

Regards,
   Dennis