[Bug 1716976] Re: DNS resolver mixes IPv6 and IPv4 caches

[gpothier]

I'm currently on 18.10 and this bug seems to have been fixed. Abam, the
bug you point to does not currently happen on my system, so maybe both
have been fixed in 18.10.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1716976

Title:
  DNS resolver mixes IPv6 and IPv4 caches

Status in systemd package in Ubuntu:
  Confirmed

Bug description:
  In our network we have a DNS server that resolves some names to local
  addresses, while the same names are resolved to our public IP when
  public DNSs are used. For instance (using fictitious names and IPs),
  xyz.mydomain.com resolves to the public IP 65.254.242.180 when using
  an external DNS server, but resolves to 192.168.0.14 when using our
  internal DNS server (which all our computers are told to use via
  DHCP).

  This used to work fine until a somewhat recent update in Ubuntu 17.10.
  Now, xyz.domain.com almost always resolves to the public IP instead of
  the internal IP. Interestingly, restarting the systemd-resolved
  service fixes the problem for a while (from a few seconds to a few
  minutes). Right after restarting the service, the dig command reports
  the expected internal IP, but after a while it gets back to reporting
  the public IP. Forcing the dig command to query our DNS server instead
  of the local resolver returns the correct IP.

  ProblemType: Bug
  DistroRelease: Ubuntu 17.10
  Package: systemd 234-2ubuntu9
  ProcVersionSignature: Ubuntu 4.12.0-13.14-generic 4.12.10
  Uname: Linux 4.12.0-13-generic x86_64
  ApportVersion: 2.20.7-0ubuntu1
  Architecture: amd64
  CurrentDesktop: ubuntu:GNOME
  Date: Wed Sep 13 13:34:50 2017
  InstallationDate: Installed on 2015-01-23 (963 days ago)
  InstallationMedia: Ubuntu-GNOME 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
  MachineType: LENOVO 20266
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.12.0-13-generic.efi.signed root=UUID=eecad38d-4fff-462c-92bc-357fa12e5515 ro quiet splash vt.handoff=7
  SourcePackage: systemd
  UpgradeStatus: Upgraded to artful on 2017-06-15 (90 days ago)
  dmi.bios.date: 03/30/2015
  dmi.bios.vendor: LENOVO
  dmi.bios.version: 76CN43WW
  dmi.board.asset.tag: No Asset Tag
  dmi.board.name: Yoga2
  dmi.board.vendor: LENOVO
  dmi.board.version: 31900058STD
  dmi.chassis.asset.tag: No Asset Tag
  dmi.chassis.type: 10
  dmi.chassis.vendor: LENOVO
  dmi.chassis.version: Lenovo Yoga 2 Pro
  dmi.modalias: dmi:bvnLENOVO:bvr76CN43WW:bd03/30/2015:svnLENOVO:pn20266:pvrLenovoYoga2Pro:rvnLENOVO:rnYoga2:rvr31900058STD:cvnLENOVO:ct10:cvrLenovoYoga2Pro:
  dmi.product.family: IDEAPAD
  dmi.product.name: 20266
  dmi.product.version: Lenovo Yoga 2 Pro
  dmi.sys.vendor: LENOVO

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1716976/+subscriptions