On Wed, 26 Sep 2007 10:38:11 +0100 <[EMAIL PROTECTED]> wrote: > > Alternatively, you could create a virtual network/link within > > the physical host, > > This is precisely what machine virtualization already does. And many > setups involve a set of physical hosts providing resources, and a set of > virtual machines consuming resources. A management system migrates the > virtual machines from host to host as it tries to make the best use of > the resources. At any given point in time, the only way to truly know > what virtual machines are on a given physical host is to ask the > physical host. > > Since the virtual machines use virtual network interfaces provided by > the physical host, this physical host can see MAC addresses and IP > addresses. >
I'm guessing that the virtual hosts/virtual network is bridged on to the physical network, so the external physical hosts and the virtual hosts are layer 2 adjacent. Where I think my suggestion is different was the idea that this virtual network is routed "onto" the physical segment, meaning that a link local multicast on the virtual network would only be seen by the virtual hosts. I think the bridging idea is a better one because it avoids introducing a layer 3 hop. However if you need to reduce layer 2 neighbour adjacencies on your physical / virtual network, or need the link-local multicast only reaches peer virtual hosts, I think setting up a virtual router would be a reasonable way to do it. > As a management problem, this can be easily solved by an agent which > runs on the physical hosts therefore I don't think the IETF needs to do > work on this problem. What would be good is for more people to implement > pure IPv6 networks on their virtual machine infrastructure and write > about it. > > Since virtualization increases the number of IP addresses consumed per > physical machine, it could lead to IPv4 exhaustion happening sooner > rather than later. By using pure IPv6 on the virtual machines there is > effectively no limit to the number of addresses that can be used, and if > someone wants to implement some kind of structured numbering system in > their /64 subnet, the bits are freely available to do this. > > This USENIX paper: > http://www.usenix.org/events/usenix06/tech/menon/menon_html/index.html > Optimizing Network Virtualization in Xen > provides some information on how one of the more popular virtualization > environments handles networking. > Thanks for the ref, I'll have a look. Regards, Mark. > --Michael Dillon > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
