Ubuntu 16.10: systemd-resolved does not resolve some domains

[vvhk]

Some domains are not resolved with default systemd-resolved set up on Ubuntu 16.10. This set up is querying the DNS server given by DHCP, and is my ISP's router.

Now, checking with `dig` directly against 192.168.1.1 (the router), dig complains that "Warning: Message parser reports malformed message packet.". And indeed, for the domains that do not resolve, this warning is always given by dig, when I query the router.

It would appear that the router or its upstream is somehow breaking the DNS packets/responses and I'll have to figure that one out separately.

The bug here is that systemd-resolved is failing on those while every other resolver seems to be working fine with those (supposedly malformed) replies. All other devices in the network, phones, windows, ubuntu 16.04, etc... are resolving with those just fine.

Most notably, I can't resolve "buy.ubuntu.com". I've captured the packet/reply I get from my router, it's attached.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: systemd 231-9ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-30.32-generic 4.8.6
Uname: Linux 4.8.0-30-generic x86_64
NonfreeKernelModules: zfs zunicode zcommon znvpair zavl nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Dec 7 11:17:43 2016
InstallationDate: Installed on 2016-11-28 (8 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
MachineType: ASUS All Series
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.8.0-30-generic root=UUID=eb750983-a34c-4b58-b5f0-a0cfa1130d1b ro
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/04/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0504
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: H81M-R
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0504:bd06/04/2015:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnH81M-R:rvrRevX.0x:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: All Series
dmi.product.version: System Version
dmi.sys.vendor: ASUS
modified.conffile..etc.systemd.resolved.conf: [modified]
mtime.conffile..etc.systemd.resolved.conf: 2016-12-07T10:46:19.412121

[Martin Pitt (pitti)]

Can you please do the following:
  sudo systemctl stop systemd-resolved.service
  sudo script -c 'SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-resolved' /tmp/resolved.log

and on another terminal "systemd-resolve buy.ubuntu.com". Then press Control-C in the first terminal and attach /tmp/resolved.log
. Thanks!

[vvhk (vvhk-deactivatedaccount-deactivatedaccount)]

Here, I've also queried just ubuntu.com which resolves fine, for reference.

[Anders Kaseorg (andersk)]

Possible duplicate of bug 1647031. For example, I see

$ dig +no{cmd,comments,stats} buy.ubuntu.com @8.8.8.8
;buy.ubuntu.com. IN A
buy.ubuntu.com. 599 IN CNAME ubuntu-advantage-cloud-guest.myshopify.com.
ubuntu-advantage-cloud-guest.myshopify.com. 3599 IN CNAME shops.myshopify.com.
shops.myshopify.com. 1799 IN A 23.227.38.32
$ dig +no{cmd,comments,stats} buy.ubuntu.com @127.0.0.53
;buy.ubuntu.com. IN A
buy.ubuntu.com. 557 IN CNAME ubuntu-advantage-cloud-guest.myshopify.com.

[vvhk (vvhk-deactivatedaccount-deactivatedaccount)]

Anders, I don't think it's a duplicate of that bug. I can resolve CNAMEs just fine with systemd-resolve. The problem that I saw was with domains that dig otherwise returned the "Message malformed" complaint.

[Launchpad Janitor (janitor)]

[Expired for systemd (Ubuntu) because there has been no activity for 60 days.]