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

[Wei Hu]

Just committed the fix in releng/10.2 branch as r286058.

Wei


> -----Original Message-----
> From: Pavel Timofeev [mailto:timp87 at gmail.com]
> Sent: Wednesday, July 29, 2015 3:48 PM
> To: Wei Hu <weh at microsoft.com>
> Cc: Slawa Olhovchenkov <slw at zxy.spb.ru>; freebsd-current at freebsd.org;
> freebsd-virtualization at freebsd.org
> Subject: Re: MS DNS doesn't answer to CURRENT under Hyper-V
> 
> Hi!
> r285785 still isn't MFCed.
> RC2 is coming soon.
> 
> 2015-07-23 10:54 GMT+03:00 Pavel Timofeev <timp87 at gmail.com>:
> > Ok, sorry!
> >
> > 2015-07-23 7:51 GMT+03:00 Wei Hu <weh at microsoft.com>:
> >> The TCP offloading is still working on these platforms. There is no flag to
> distinguish UDP and TCP offloading, so the RXCSUM and TXCSUM are still set.
> Let me know if there is any other way to show it properly.
> >>
> >> Thanks,
> >> Wei
> >>
> >>
> >> -----Original Message-----
> >> From: Pavel Timofeev [mailto:timp87 at gmail.com]
> >> Sent: Wednesday, July 22, 2015 9:04 PM
> >> To: Wei Hu <weh at microsoft.com>
> >> Cc: Slawa Olhovchenkov <slw at zxy.spb.ru>; freebsd-
> current at freebsd.org;
> >> freebsd-virtualization at freebsd.org
> >> Subject: Re: MS DNS doesn't answer to CURRENT under Hyper-V
> >>
> >> Hi! I see you have done the code for disabling UDP checksum
> >> offloading when running on the Hyper-V on Windows Server 2012 and
> >> earlier hosts
> >>
> >> https://svnweb.freebsd.org/base?view=revision&revision=285785
> >>
> >> I tried new CURRENT and it works. Thank you!
> >>
> >> A small note here: while it disables and works it still shows RXCSUM and
> TSCSUM in iface's options:
> >>
> >> root at proxy:/usr/src # ifconfig hn0
> >> hn0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric
> 0 mtu 1500
> >>
> options=31b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,TSO4,TSO6>
> >>         ether 00:15:5d:02:9c:09
> >>         inet 192.168.25.26 netmask 0xffffffc0 broadcast 192.168.25.63
> >>         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
> >>
> >> Is it possible to hide it automatically if it's disabled by new code?
> >>
> >>
> >> 2015-07-13 11:06 GMT+03:00 Wei Hu <weh at microsoft.com>:
> >>> We have root caused the problem. This issue happens on the Hyper-Vs
> on Windows Server 2012 (Win 8.0) and earlier releases. On these releases,
> the UPD checksum offloading on host side does not work properly. The
> workaround is to disable UPD checksum offloading in the FreeBSD guest
> through 'ifconfig'. We are also working on a patch to turn off UPD checksum
> offloading in the netvsc driver when detecting the Hyper-V releases.
> >>>
> >>> The UDP checksum offloading works fine on Windows Server 2012R2 and
> Win 8.1 hosts.
> >>>
> >>> Thanks Pavel and Slawa for the support.
> >>>
> >>> Wei
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: owner-freebsd-virtualization at freebsd.org
> >>>> [mailto:owner-freebsd- virtualization at freebsd.org] On Behalf Of
> >>>> Pavel Timofeev
> >>>> Sent: Wednesday, July 8, 2015 4:06 PM
> >>>> To: Slawa Olhovchenkov
> >>>> Cc: freebsd-current at freebsd.org; freebsd-virtualization at freebsd.org
> >>>> Subject: Re: MS DNS doesn't answer to CURRENT under Hyper-V
> >>>>
> >>>> Ok, r284746 is the root of the problem. MS DNS works under r284745
> >>>> and doesn't work under r284746.
> >>>> Slawa, what should I look at in wireshark output?
> >>>>
> >>>>
> >>>> 2015-07-07 18:49 GMT+03:00 Slawa Olhovchenkov <slw at zxy.spb.ru>:
> >>>> > On Tue, Jul 07, 2015 at 06:04:46PM +0300, Pavel Timofeev wrote:
> >>>> >
> >>>> >> Well, turning off checksum offloading by `ifconfig hn0 -txcsum
> >>>> >> -rxcsum` definitely helps.
> >>>> >>
> >>>> >> As for tcpdump I'm not completely sure if I did it right, but I
> >>>> >> see "bad udp cksum" phrase:
> >>>> >>
> >>>> >> # tcpdump -i hn0 -vvv -nn udp dst port 53
> >>>> >> tcpdump: listening on hn0, link-type EN10MB (Ethernet), capture
> >>>> >> size
> >>>> >> 262144 bytes
> >>>> >> 18:01:19.139994 IP (tos 0x0, ttl 64, id 61218, offset 0, flags
> >>>> >> [none], proto UDP (17), length 51)
> >>>> >>     192.168.25.26.45683 > 192.168.25.3.53: [bad udp cksum 0xb39e
> >>>> >> -> 0xf210!] 52886+ A? ya.ru. (23)
> >>>> >> 18:01:24.140544 IP (tos 0x0, ttl 64, id 17293, offset 0, flags
> >>>> >> [none], proto UDP (17), length 51)
> >>>> >>     192.168.25.26.12575 > 192.168.25.3.53: [bad udp cksum 0xb39e
> >>>> >> -> 0x7365!] 52886+ A? ya.ru. (23)
> >>>> >
> >>>> > tcpdump "bad udp cksum" is normal on FreeBSD host in case
> >>>> > checksum offload (and may be need only for help finding issuse in
> code).
> >>>> > Need wireshark capturing from MS DNS host (or from mirroring port).
> >>>> _______________________________________________
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> >>>> http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization
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