Arch Linux

Inchw0rm

Member

Registered: 2013-05-12

Posts: 25

[SOLVED] DNS resolution extremely slow

Hello there,

I'm having trouble retrieving databases and files with pacman. I can browse the internet normally, however I get the following error:

inchw0rm@blackrose ~ % sudo pacman -Syy
[sudo] password for inchw0rm: 
:: Synchronizing package databases...
error: failed retrieving file 'core.db' from ftp.halifax.rwth-aachen.de : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'core.db' from mirror.system.is : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'core.db' from mirror.i3d.net : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'core.db' from mirror.koddos.net : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'core.db' from mirror.ams1.nl.leaseweb.net : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'core.db' from mirror.neostrada.nl : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'core.db' from archlinux.mirror.wearetriple.com : Resolving timed out after 10519 milliseconds
 core                                                                         130.4 KiB  1060K/s 00:00 [#############################################################] 100%
error: failed retrieving file 'extra.db' from ftp.halifax.rwth-aachen.de : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'extra.db' from mirror.system.is : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'extra.db' from mirror.i3d.net : Resolving timed out after 10519 milliseconds
error: failed retrieving file 'extra.db' from mirror.koddos.net : Resolving timed out after 10519 milliseconds
error: failed retrieving file 'extra.db' from mirror.ams1.nl.leaseweb.net : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'extra.db' from mirror.neostrada.nl : Resolving timed out after 10519 milliseconds
error: failed retrieving file 'extra.db' from archlinux.mirror.wearetriple.com : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'extra.db' from mirror.yandex.ru : Resolving timed out after 10521 milliseconds
error: failed to update extra (download library error)
error: failed retrieving file 'community.db' from ftp.halifax.rwth-aachen.de : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'community.db' from mirror.system.is : Resolving timed out after 10518 milliseconds
error: failed retrieving file 'community.db' from mirror.i3d.net : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'community.db' from mirror.koddos.net : Resolving timed out after 10519 milliseconds
error: failed retrieving file 'community.db' from mirror.ams1.nl.leaseweb.net : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'community.db' from mirror.neostrada.nl : Resolving timed out after 10520 milliseconds
error: failed retrieving file 'community.db' from archlinux.mirror.wearetriple.com : Resolving timed out after 10521 milliseconds
error: failed retrieving file 'community.db' from mirror.yandex.ru : Resolving timed out after 10519 milliseconds
error: failed to update community (download library error)

as you can see, I am able to resolve host names via the 'problematic' connection:

inchw0rm@blackrose ~ % host google.com
google.com has address 172.217.23.174
google.com has IPv6 address 2a00:1450:4001:820::200e
google.com mail is handled by 50 alt4.aspmx.l.google.com.
google.com mail is handled by 30 alt2.aspmx.l.google.com.
google.com mail is handled by 20 alt1.aspmx.l.google.com.
google.com mail is handled by 10 aspmx.l.google.com.
google.com mail is handled by 40 alt3.aspmx.l.google.com.
inchw0rm@blackrose ~ % host ftp.halifax.rwth-aachen.de
ftp.halifax.rwth-aachen.de has address 137.226.34.46
ftp.halifax.rwth-aachen.de has IPv6 address 2a00:8a60:e012:a00::21
inchw0rm@blackrose ~ %
inchw0rm@blackrose ~ % 
inchw0rm@blackrose ~ % ping ftp.halifax.rwth-aachen.de
PING ftp.halifax.rwth-aachen.de (137.226.34.46) 56(84) bytes of data.
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=1 ttl=48 time=24.3 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=2 ttl=48 time=29.5 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=3 ttl=48 time=29.5 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=4 ttl=48 time=22.2 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=5 ttl=48 time=22.1 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=6 ttl=48 time=23.2 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=7 ttl=48 time=21.2 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=8 ttl=48 time=24.1 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=9 ttl=48 time=22.0 ms
64 bytes from ftp.halifax.rwth-aachen.de (137.226.34.46): icmp_seq=10 ttl=48 time=23.0 ms
^C
--- ftp.halifax.rwth-aachen.de ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 13077ms
rtt min/avg/max/mdev = 21.249/24.174/29.585/2.852 ms
inchw0rm@blackrose ~ %  

strangely it does work over wi-fi (which is another subnetwork), the problem occurs only with ethernet.
Disabling ipv6 doesn't do anything.
Advice where to look at needed.

UPD: resolving host names works, but takes a lot of time.

UPD: I further investigated the problem, and as it seems it has nothing to do with pacman. It has something to do with the network. That's also the reason why I renamed the topic. Any way all other machines seem to work fine, so I assume it's something with my arch linux laptop.

Best

Last edited by Inchw0rm (2018-04-19 14:24:01)

seth

Member

Registered: 2012-09-03

Posts: 51,017

Re: [SOLVED] DNS resolution extremely slow

cat /etc/nsswitch.conf

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Inchw0rm

Member

Registered: 2013-05-12

Posts: 25

Re: [SOLVED] DNS resolution extremely slow

Ok, it was a faulty network socket. Thanks everyone.