Re: [Qemu-discuss] Virtual desktops network and port numbers

[Tony Su]

 The way I understand it,

The port number is only critical for display mapping which would be
particularly important if all Guests are deployed on the same machine,
the machines are sharing the Host's IP address and you are logged into
the Host wanting to view any/all Guests.

But, this all becomes relatively moot if you configure each Guest with
its own IP address (IMO most common so that Network Services like DNS
better understand the location of each machine both virtual and
physical)
If each machine is accessible with a different IP address, then you
can also configure any port number both same or different and still be
unique on the network.

In other words...
Conceptually it should be helpful to understand what is typically
configured <in> the Guest and what is configured as Guest properties.
Separate and categorize where a configuration is, and you'll then be
able to more easily recognize the bottom line combined effect.

Tony

On Fri, May 29, 2015 at 12:13 AM, Lucio Crusca <address@hidden> wrote:
> Hello,
>
> I'm planning a local network where all the desktops are virtual guests used
> over SPICE. There is requirement I need to address, and I don't understand
> how. It's the fact that each user must be able to use his/her guest from
> each client.
>
> I don't know if this requirement already has a specific name and a common
> solution, it seems to me a very common requirement, however I fail to
> understand what the solution is, when using qemu+kvm+libvirt+spice, so I'll
> try to explain the problem in more detail.
>
> Let's say Joe today sits at client4 and he wants to use his virtual desktop,
> namely guest9. Server side, guest9 is a virtual machine listening over spice
> at TCP port 3051. That means remote-viewer on client4 should ask Joe for
> authentication and then connect to the server using port 3051, because Joe's
> desktop is the one named guest9, which is listening on port 3051. How does
> remote-viewer become aware of the correct port number for Joe?
>
> I understand there's something basically wrong in my reasoning, because
> remote-viewer needs a port to connect to before authentication even starts,
> so there must be something in the spice protocol that somehow multiplexes a
> single port to many guest, RPC portmapper style, but I've failed to find
> even a faded trace of it in the docs...
>