suppose I have an environment with self hosted engine environment in 4.1

How is it generated the hw address of the virtual nic of the engine vm when I deploy using cockpit?

Suppose on a lan I already have a self hosted engine environment and I'm going to create another one on the same lan, is there any risck of hw address collision for the engine?

I know that from inside web admin console I can then set the hw address ranges for the VMs, but what about the mac of the engine vm itself?

At the moment I have only lan access and so crosschecked an RHV 4.1 environment and I see that the engine has hw addr 00:16:3e:7c:65:34 (a lookup seems to associate to "Xensource, Inc.") while the VMs have their hw addr in the range 00:1a:4a:16:01:51 - 00:1a:4a:16:01:e6 (eg the 00:1a:4a:16:01:56) (a lookup seems to associate to "Qumranet Inc.".

Does this mean that the engine has a sort of dedicated range? Any risk of collision or is a query on the lan done before assigning it? 

BTW: probably the range for engine VM hw addr has to be put in Qumranet too...?

Thanks in advance,

Gianluca