RedHat VirtIO IPv6 offloading on Windows 2012 and 2008

[Dominik Bay]

Hi,

just a short heads-up before anyone else is burning 16 or more hours of
his life on this issue:

Apparently the Win7 / Win8 drivers packaged in virtio-win-0.1-52.iso do
have a bug in IPv6 TCP and UDP offloading.

I have following setup:

VLAN10 - 2001:db8:10::/64
Solaris (Hypervisor) - Windows 2012 (KVM) - Windows 2008 (KVM)

- Layer3 network -

VLAN20 - 2001:db8:20::/64
Windows 2008 (bare-metal)

The hypervisor can communicate with the bare-metal win2k8 (ICMP, UDP, TCP).
Both VMs can't (only ICMP works). UDP and TCP packets are received by
the bare-metal Win2k8 (visible in Wireshark) but they get silently dropped.

Disable offloading, be happy (as in most cases :-/).

-dominik