[Planetlab-devel] IPv6 support for MyPLC

[Marc E. Fiuczynski]

Hello Maoke,

> Marc has mentioned a method to substitute FF:FE in the eui-64 format
> with the sliver id. i think this is a good idea. on the other hand, if
> we can get a special company id (first 24 bits in MAC address) for
> vserver like xen or vmware, why don't we do this? ;-)

What is involved in applying for this company id?

How does VMware/Xen generate unique MAC addresses per VM in a LAN with
potentially 100s of physical machines with each of which having, say, 100
VMs?  Do they simply rely on a good random algorithm to select the lower 24
bits of the MAC and then rely on ICMPv6 "duplicate address detection" (DaD)
to make sure no one else is using that address?   What happens when an
administrator rewires a physical machine (unplugging it for say 10 seconds)
and on a different physical machine a VM comes online selecting a virtual
MAC# that already is being used by a VM on the unplugged physical machine?
In such a scenario, the ICMPv6 DAD code will claim that the newly select
address is ok, but then all hell will break loose when the admin plugs the
unplugged machine back in.  While this might appear like one of those "one
in a million" events, my guess is that it wouldn't be so rare.  Ideally, I'd
like to just avoid this altogether somehow by using a scheme that can
operate 100% using autoconf rather than having to rely on some sort of
centralized or coordinated DHCPv6 service.

Marc