systemd-resolved does not allow you to connect using subdomains using search domains which are in /etc/resolv.conf

[Sean Crosby]

systemd-resolved doesn't seem to allow you to use subdomains when connecting to hosts in domains that are part of /etc/resolv.conf

e.g.

16:01|scrosby@stewie: ~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver W.X.Y.Z
nameserver A.B.C.D
nameserver 127.0.0.53
search blah1 blah2 blah3 blah4 blah5

with systemd-resolved running

16:05|scrosby@stewie: ~$ ping foo.bar
ping: foo.bar: Name or service not known

without systemd-resolved running

16:05|scrosby@stewie: ~$ ping foo.bar
PING foo.bar.blah3 (E.F.G.H) 56(84) bytes of data.
64 bytes from foo.bar.blah3 (E.F.G.H): icmp_seq=1 ttl=52 time=1.68 ms
64 bytes from foo.bar.blah3 (E.F.G.H): icmp_seq=2 ttl=52 time=1.09 ms

It does seem like looking up hosts without a . in their name does use the search domains in resolv.conf though

16:05|scrosby@stewie: ~$ ping foo2
PING foo2.blah3 (I.J.K.L) 56(84) bytes of data.
64 bytes from foo2.blah3 (I.J.K.L): icmp_seq=1 ttl=52 time=1.34 ms
64 bytes from foo2.blah3 (I.J.K.L): icmp_seq=2 ttl=52 time=1.29 ms

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: systemd 231-9git1
ProcVersionSignature: Ubuntu 4.8.0-26.28-generic 4.8.0
Uname: Linux 4.8.0-26-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
Date: Tue Oct 25 16:13:38 2016
InstallationDate: Installed on 2016-06-08 (139 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
MachineType: Dell Inc. OptiPlex 990
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.8.0-26-generic root=UUID=67011022-ac91-464f-ab8f-c97c6cb5a439 ro quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: Upgraded to yakkety on 2016-10-24 (0 days ago)
dmi.bios.date: 08/26/2015
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A19
dmi.board.asset.tag: UOM97917
dmi.board.name: 0VNP2H
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.asset.tag: UOM97917
dmi.chassis.type: 3
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA19:bd08/26/2015:svnDellInc.:pnOptiPlex990:pvr01:rvnDellInc.:rn0VNP2H:rvrA00:cvnDellInc.:ct3:cvr:
dmi.product.name: OptiPlex 990
dmi.product.version: 01
dmi.sys.vendor: Dell Inc.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Benjamin Drung (bdrung)]

I am seeing the exact same behavior on my Ubuntu 16.10 (yakkety) machine.

[Benjamin Drung (bdrung)]

The workaround described above solved the issue:

$ systemctl disable systemd-resolved.service

[Michał Sawicz (saviq)]

Same issue here, my dhcp sends "bar.name" and "name" as search domains, systemd-resolve --status reports them correctly:

Link 1 (enxxxxxxxxxxxx)
      Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
       LLMNR setting: yes
MulticastDNS setting: no
      DNSSEC setting: allow-downgrade
    DNSSEC supported: no
         DNS Servers: 10.1.0.1
          DNS Domain: bar.name
                      name

But:

 ping foo
PING foo.bar.name (10.1.0.2) 56(84) bytes of data.
[...]

 ping foo.bar
ping: foo.bar: Name or service not known

 ping foo.bar.name
PING foo.bar.name (10.1.0.2) 56(84) bytes of data.
[...]

[Martin Pitt (pitti)]

I'm afraid this is by design and wontfix, see https://github.com/systemd/systemd/issues/4821#issuecomment-264995354 for details. This isn't something which we reasonably can/should change downstream, so I suggest to direct discussions to the upstream bug. Thanks!

[Vincent Gerris (vgerris)]

Again Martin, this is NOT a solution.
A fix would be something that avoids the problem from emerging in the first place.
If stopping systemd-resolvd is a solution, that let's make sure it is NOT enabled nor installed in 17.04 by default and let's FIX it to be the same in 16.10 if possible.

Thank you