[Engine-devel] network subnet

[Alon Bar-Lev]

----- Original Message -----
> From: "Livnat Peer" <lpeer at redhat.com>
> To: "Alon Bar-Lev" <alonbl at redhat.com>
> Cc: engine-devel at ovirt.org
> Sent: Thursday, August 30, 2012 10:16:05 PM
> Subject: Re: [Engine-devel] network subnet
> 
> On 30/08/12 21:39, Alon Bar-Lev wrote:
> > 
> > 
> > ----- Original Message -----
> >> From: "Livnat Peer" <lpeer at redhat.com>
> >> To: engine-devel at ovirt.org
> >> Sent: Thursday, August 30, 2012 3:22:29 PM
> >> Subject: [Engine-devel] network subnet
> >>
> >> Hi All,
> >>
> >> Today when a user wants to define a network subnet mask, he does
> >> it
> >> when
> >> he attaches the network to a host NIC.
> >>
> >> I was wondering if there is a reason not to define the network
> >> subnet
> >> on
> >> the logical network entity (Data center level).
> >>
> >> Thanks, Livnat
> > 
> > Hello,
> > 
> > I am sorry, maybe I do not understand... the IP scheme enforces the
> > use of address mask in order to properly route packets.
> 
> of course. My proposal is related to our user usage of the system.
> Today
> ovirt user, who wants to define a network subnet, has to type the
> subnet
> per host (per network), I think the user should only define it once
> on
> the logical network entity in the Data Center.
> Propagating the value to all hosts is needed but it should be our
> internal implementation detail.
> 
> > 
> > Network mask is used in any case, I guess it can be dropped from
> > configuration in favour of using the address class as mask, is
> > that what you suggest?
> > 
> 
> No, hope the above paragraph made it more clear.
> 

Hello,

Then you assume that a logical network, which is actually layer 2 network in our implementation, has layer 3 characteristics, right?

In our current implementation "data center logical network" is pure layer 2 segment aka layer 2 broadcast domain.

One can use the same logical network for multiple layer 3 segments, which is totally valid and consistent with standard physical layer 2 setup.

Unless I am missing something crucial, I would suggest to keep the consistent physical->virtual mapping, unless we emulate layer 3 switching. Layer 2 does not have layer 3 characteristics.

Regards,
Alon.