DNS lookup through Netgear DG834G V4 router slow or times out

Bug #1609546 reported by Colin Law on 2016-08-03
This bug affects 5 people
Affects Status Importance Assigned to Milestone
systemd (Ubuntu)

Bug Description

On Zesty I am seeing a timeout both with systemd-resolve and dnslookup rather than just a slow resolution. The workaround in comment #6 which disables DNSSEC still corrects the problem.

On up to date Yakkety if I specify my Netgear router as the DNS server (via Network Manager) then DNS lookup takes about 30 seconds. I see the delay when I run, for example,
systemd-resolve www.google.com
wget www.google.com

I do not see the same delay if I run
nslookup www.google.com

A clue may be that in syslog I see
Aug 3 21:20:56 dibbler systemd-resolved[2362]: Using degraded feature set (UDP+EDNS0+DO) for DNS server
Aug 3 21:21:16 dibbler systemd-resolved[2362]: Using degraded feature set (UDP+EDNS0) for DNS server
Aug 3 21:21:32 dibbler systemd-resolved[2362]: Using degraded feature set (UDP) for DNS server

I do not see the issue if I specify an external DNS server.
I do not see the issue on 16.04, nor previous versions, or on other devices connected to the network. I have been using this router for years.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: systemd 231-1
ProcVersionSignature: Ubuntu 4.4.0-33.52-generic 4.4.15
Uname: Linux 4.4.0-33-generic x86_64
ApportVersion: 2.20.3-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Aug 3 21:24:07 2016
InstallationDate: Installed on 2016-08-02 (1 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Alpha amd64 (20160802)
MachineType: Hewlett-Packard Presario CQ57 Notebook PC
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-33-generic root=UUID=aaca48e9-0f14-4b6b-ad60-fe93989c14b8 ro quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/17/2011
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: F.47
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 3577
dmi.board.vendor: Hewlett-Packard
dmi.board.version: 24.49
dmi.chassis.asset.tag: Chassis Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnHewlett-Packard:bvrF.47:bd12/17/2011:svnHewlett-Packard:pnPresarioCQ57NotebookPC:pvr068E120000204910000620100:rvnHewlett-Packard:rn3577:rvr24.49:cvnHewlett-Packard:ct10:cvrChassisVersion:
dmi.product.name: Presario CQ57 Notebook PC
dmi.product.version: 068E120000204910000620100
dmi.sys.vendor: Hewlett-Packard

Colin Law (colin-law) wrote :
Colin Law (colin-law) wrote :

Having updated the router to the latest firmware (5.01.17) the problem appears to be resolved (even though the release notes made no mention of DNS. Marking this bug as invalid.

Changed in systemd (Ubuntu):
status: New → Invalid
Colin Law (colin-law) wrote :

I am marking this New again as it has not actually been fixed by upgrading the router. It now appears that the symptom is intermittent. I have not been able to determine what it is that triggers it to fail or work.

Changed in systemd (Ubuntu):
status: Invalid → New
Martin Pitt (pitti) wrote :

Can you please generate a debug log for resolving a name when this takes a long time?

  sudo systemctl stop systemd-resolved
  sudo SYSTEMD_LOG_LEVEL=debug script -c /lib/systemd/systemd-resolved /tmp/debug.txt

then in another terminal

  systemd-resolve www.google.com

Control-C the resolved process in the first terminal, and attach /tmp/debug.txt here. Thanks!

Changed in systemd (Ubuntu):
status: New → Incomplete
Colin Law (colin-law) wrote :
Changed in systemd (Ubuntu):
status: Incomplete → New
Martin Pitt (pitti) wrote :

Thanks! I forwarded this to https://github.com/systemd/systemd/issues/3980 .

Can you please try how this behaves when disabling DNSSEC?

  printf '[Resolve]\nDNSSEC=no\n' | sudo tee /etc/systemd/resolved.conf.d/nodnssec.conf
  sudo systemctl restart systemd-resolved

and then resolve something?

Colin Law (colin-law) wrote :

Disabling DNSSEC appears to have solved the problem.
(I had to manually create /etc/systemd/resolved.conf.d/ before the command would run)

Martin Pitt (pitti) wrote :

Thanks for checking. So you can keep this workaround in place for the time being.

Changed in systemd (Ubuntu):
importance: Undecided → Medium
status: New → Triaged
Colin Law (colin-law) wrote :

Thanks Martin.

I'm seeing a similar issue on current Ubuntu Yakkety with Android phone AP via WPA2-personal:

$ systemd-resolve www.guugle.com
-- Information acquired via protocol DNS in 13.6889s.
-- Data is authenticated: no

`host www.guugle.com` and nslookup on the other hand return immediately during this time. Disabling DNSSEC and restarting systemd-resolved using the instructions above has no effect (the above trace is after disabling).

syslog contains the lines:

Oct 31 20:25:41 xxxxx systemd-resolved[5309]: Using degraded feature set (UDP+EDNS0+DO) for DNS server

resolv.conf contains only `nameserver`. The problem disappears if I add also the line `nameserver` (that's the upstream DNS) --- however, the following line appears in the logs:

Oct 31 20:34:05 xxxxx systemd-resolved[5309]: Using degraded feature set (UDP) for DNS server

Colin Law (colin-law) on 2017-02-21
tags: added: zesty
Gannet (ken20001) wrote :

Hello. I'm recently upgraded to Zesty and the same messages in journalctl (too many):

бер 05 14:33:56 p5q3 systemd-resolved[1223]: Using degraded feature set (UDP) for DNS server


~$ nslookup google.com
;; connection timed out; no servers could be reached


~$ systemd-resolve google.com

-- Information acquired via protocol DNS in 65.9ms.
-- Data is authenticated: no

Also, I'm experiencing some difficulties connecting by some software, for example teamviewer can't connect at all.

Gannet (ken20001) on 2017-03-05
summary: - Slow DNS lookup through Netgear DG834G V4 router
+ nslookup not working
summary: - nslookup not working
+ nslookup doesn't resolves
summary: - nslookup doesn't resolves
+ nslookup doesn't works

@Gannet, I don't understand why you have changed the description. For me I see a slow lookup, it does eventually resolve. Does the workaround in #6 fix it? If not then it is a different bug.

@Colin, can you please reply to what upstream asked?

summary: - nslookup doesn't works
+ Slow DNS lookup through Netgear DG834G V4 router
Colin Law (colin-law) wrote :

I have replied to the upstream comment, however with Zesty I am seeing a slightly different symptom. Both systemd-resolve and nslookup both timeout rather than just being slow. Disabling DNSSEC still fixes it however.

Colin Law (colin-law) on 2017-03-24
summary: - Slow DNS lookup through Netgear DG834G V4 router
+ DNS lookup through Netgear DG834G V4 router slow or times out
description: updated
Colin Law (colin-law) wrote :

This is particularly annoying when installing Ubuntu, as the system knows the network is connected, but DNS does not work so it can't actually do anything useful.

Laurent Simon (stratic) wrote :

Same case than Gannet after Zesty upgrade. Disabling DNSEC does not fix anything.

Colin Law (colin-law) wrote :

Laurent, if disabling DNSSEC does not fix it then it is not the same bug. I suggest submitting a new bug.

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