aseques
Posts: 6
Joined: Fri Jun 21, 2013 8:46 am

DNS from dhcp don't work 'temporary failure in name resolution' for ping

Wed Jul 10, 2019 8:06 am

I have just installed the current raspbian (june 2019) on my raspberry, my network layout is typical 192.168.1.0/24 with dhcp and DNS provided by two Windows Active directory servers and I am connected via ethernet.
I have never had an issue with dns other than with this raspberry setup (and I'd rather keep the things standard in the raspbian side)

I haven't done any configuration changes on the raspberry from the default configuration (other than enabling ssh)
  • dhcpd checks:
    With the command "sudo dhcpcd -o domain_name_servers -T" I get a lot of information and among it:
    new_domain_name_servers='192.168.1.19 192.168.1.20 127.0.0.1'
  • systemd-resolve checks
    With the command "systemd-resolve --status" I get only a single dns server as output
    DNS Servers: 127.0.0.1
So it seems to me that altough dhcpd is receiving the proper name servers, it's not propagating them to the resolvers ("option domain_name_servers, domain_name, domain_search, host_name" is enabled by default)

I could add dnsmasq in the mix, but if possible I would like to have the most standard possible system.


UPDATE: possible related issue here

aseques
Posts: 6
Joined: Fri Jun 21, 2013 8:46 am

Re: DNS from dhcp don't work 'temporary failure in name resolution' for ping

Wed Jul 10, 2019 9:25 am

I finally found the clue from this post, basically the issue is that the installed package to replace resolvconf (named openresolv) doesn't have all the capabilites (or it has some bugs), so it ends with an invalid configuration. It can be fixed by reverting to the old program:

Code: Select all

apt-get install resolvconf #it will take care of removing the openresolv
After that, the file should read:
# 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 192.168.1.19
nameserver 192.168.1.20
search example.com

epoch1970
Posts: 3802
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: DNS from dhcp don't work 'temporary failure in name resolution' for ping

Wed Jul 10, 2019 11:24 am

This is a thread bump more or less, I think the topic might need some more visibility.

https://wiki.archlinux.org/index.php/Systemd-resolved
https://www.freedesktop.org/software/sy ... rvice.html

Idiosyncrasies I have seen so far:
- The systemd resolver might default to using Google's public DNS servers 8.8.8.8
- openresolv and/or systemd-resolved might have issues parsing DNS info handed by DNS clients

Hoping someone knowledgeable will chip in.
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

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