VM systems and IPv6?

YOSHIFUJI Hideaki yoshfuji at linux-ipv6.org
Thu Mar 18 08:12:40 CET 2010

Phil Pennock wrote:

> How common is it these days to have people using Windows under VMs?
> How common is it for VM virtual bridges to somehow be breaking IPv6?
> It really looks as though neighbour solicitations are not making it
> across, which begs the question of how did the VM get its address
> configured up in the first place.
> Anyone have any better thoughts?  Am I going to say "doh"?
> Which returns to my second question.  Are there VM environments that do
> work with IPv6?

Well, I guess you're using wireless NIC in your host machine.
If so, I'd say that bridging is not friendly with wireless NIC.

 - source address cannot be "forged"; you cannot use
   another source MAC address, e.g. one assigned on your
   VM's interface.
 - you cannot set "promiscuous" mode on your Wireless card;
   you cannot get unicast traffic for your guests.

Even with these restrictions, multicast traffic (e.g. unsolicited
RAs etc.) can reach your VMs, so VM can have global address.
Too bad.

To solve these issues, host machine needs to have ND Proxy (RFC4389)
or similar.

Or, as a workaround, disable IPv6 on your VMs. (sigh...)



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