RE: MS DNS doesn't answer to CURRENT under Hyper-V

> -----Original Message-----
> From: owner-freebsd-virtualization_at_freebsd.org [mailto:owner-freebsd-
> virtualization_at_freebsd.org] On Behalf Of Pavel Timofeev
> Sent: Tuesday, July 7, 2015 7:51 PM
> To: freebsd-current_at_freebsd.org; freebsd-virtualization_at_freebsd.org
> Subject: MS DNS doesn't answer to CURRENT under Hyper-V
> 
> Hi!
> I have a test virtual machine which runs CURRENT under Hyper-V. It's
> amd64 r285198 now.
> It can't get any response from MS DNS server. Well, it could two or three
> weeks ago, but after upgrade it's not able to do it anymore.
> Google DNS answers without problems meanwhile (sic!).
> 
> What I do:
> # host google.ru 192.168.25.3
> I see that MS DNS (192.168.25.3) server receives these packets, but ignores
> them.
> And no matter how my system asks MS DNS. Every daemon can't get
> response too.
> 
> I know that nothing was changed in MS DNS server. No doubt.
> Then I tried different available CURRENT snapshot ISOs.
> 
> FreeBSD-11.0-CURRENT-amd64-20150630-r284969-disc1.iso - MS DNS does
> not answer.
> 
> FreeBSD-11.0-CURRENT-amd64-20150625-r284814-disc1.iso - MS DNS does
> not answer.
> 
> FreeBSD-11.0-CURRENT-amd64-20150618-r284544-disc1.iso - MS DNS
> answers!
> 
> So something was committed to CURRENT between 20150618 and 20150625.
> This something ruins communication with MS DNS.
> 
There was a commit for Hyper-V TSO and checksum offloading support  (r284746) on 
June 24th. I think this commit is the cause. Can you verify the MS DNS behavior between
The builds of June 23rd and 24th? I will take a look of this issue tomorrow.

Thanks,
Wei