On Sat, Nov 30, 2019 at 03:59:54PM +0000, Richard M wrote:

Hello I found under networking in the Domain XML 'Multcast tunnel'. My question is does anyone know what is the intended use of multicast tunnel networking?What are the potential pitfalls of using such a configuration other than what's highlighted in the domain xml. eg: can it suffer from throughput issues? Can the tunnel be accessed from outside Libvirt? I'm struggling to find any information about it. If anyone has any information about it, Or where I can obtain such information it would be appreciated.

This is something that has been supported by QEMU forever, but I think it is fair to say it is rarely used. The main use case would be setting up network communication between a group in QEMU instances (possibly across hosts) in a case where you don't have access to any better technology such as tap device + bridging. eg if you are an unprivileged user & cannot get root. I doubt performance is going to be anything special. There's also no meaningful security - any user or process or host can send & receive on the same multicast address. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|