[ovirt-users] Re: self hosted engine mac range and possible conflict

On Wed, May 9, 2018 at 4:21 PM, Gianluca Cecchi <gianluca.cecchi(a)gmail.com > wrote: > Hello, > 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? > It has been discussed here: https://bugzilla.redhat.com/show_bug.cgi?id=1244502 In a few worlds: the proposed HE MAC address are explicitly on a different range just to minimize collision risks on complex scenarios.