[SOLVED] how to use dns on non-NetworkManager Debian Stretch correctly?

erik2282 · 11-16-2017, 04:52 PM

debian Stretch
Not using NetworkManager, dont want to use it. on my debian jessie machine, using networking instead of NetworkManager works fine, but cant get dns to work on stretch...

Code:

root@stretchmachine:~# systemctl status NetworkManager
● NetworkManager.service - Network Manager
   Loaded: loaded (/lib/systemd/system/NetworkManager.service; disabled; vendor preset: enable
   Active: inactive (dead)
     Docs: man:NetworkManager(8)

Nov 16 16:31:47 stretchmachine systemd[1]: Network Manager is not active.

Code:

root@stretchmachine:~# systemctl status networking
● networking.service - Raise network interfaces
   Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
   Active: active (exited) since Thu 2017-11-16 16:31:49 CST; 4min 29s ago
     Docs: man:interfaces(5)
  Process: 572 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=0/SUCCESS)
  Process: 298 ExecStartPre=/bin/sh -c [ "$CONFIGURE_INTERFACES" != "no" ] && [ -n "$(ifquery 
 Main PID: 572 (code=exited, status=0/SUCCESS)
    Tasks: 0 (limit: 4915)
   CGroup: /system.slice/networking.service

Nov 16 16:31:47 stretchmachine systemd[1]: Starting Raise network interfaces...
Nov 16 16:31:49 stretchmachine systemd[1]: Started Raise network interfaces.

This is what I was getting at the bottom of vi editor when i try to edit /etc/resolv.conf

Code:

"/etc/resolv.conf"
"/etc/resolv.conf" E166: Can't open linked file for writing
Press ENTER or type command to continue

i noticed it had a link so i deleted, recreated, and put my dns, domain, and search in there.

Code:

root@stretchmachine:/etc# ls -latr resolv.conf 
lrwxrwxrwx 1 root root 35 Nov 16 14:35 resolv.conf -> /var/run/NetworkManager/resolv.conf
root@stretchmachine:/etc# rm resolv.conf 
root@stretchmachine:/etc# ls -latr resolv.conf 
ls: cannot access 'resolv.conf': No such file or directory
root@stretchmachine:/etc# vi resolv.conf
root@stretchmachine:/etc# ping google.com
ping: google.com: Name or service not known

but can ping local and internet IP's all day

Code:

root@stretchmachine:/etc# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=57 time=7.98 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=57 time=7.32 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=57 time=7.32 ms
^C
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 7.321/7.542/7.983/0.327 ms

lazydog · 11-16-2017, 10:02 PM

In order to use host names instaed of IP Addresses you need to configure your resolv.conf file.
HERE are soem examples of what needs to be placed into the resolv.conf file.
Be aware if you are using DHCP then this file should be over written by what the DHCP server supplies.

erik2282 · 11-16-2017, 11:04 PM

Thanks. Yes I know that I have to use that file. In my post I said that I was using that file and still DNS doesn't work.

IsaacKuo · 11-17-2017, 02:47 AM

Did you actually remove the network-manager?

Code:

apt-get remove --purge network-manager

My experience is that you have to actually remove the package in order to get rid of that annoying /etc/resolv.conf link across reboots. I had to do this in Debian 9 Squeeze, but I did not have to do this in Debian 8 Jessie.

After getting rid of the annoying /etc/resolv.conf link, I manually created my own /etc/resolv.conf using my gateway's IP address:

Code:

nameserver 192.168.0.1

erik2282 · 11-17-2017, 09:44 AM

No I didn't remove Network Manager. Is this something new that has to be done in Debain 9 to use the networking service instead of Network Manager? In all my centos and debian machines in the past I've never had to uninstall Network Manager, I've always just disabled the service. I guess I can try it, though.

I've never seen that sym link before on other operating systems, this is the first time. I did rm the file and recreate it myself and my i have my dns server in resolv.conf. Anyway I rebooted, still with network manger installed but service disabled, and the link did not recreate itself.

erik2282 · 11-17-2017, 09:52 AM

ahh!! So after removing network-manager i tested pinging a hostname, and still couldn't ping. I check resolv.conf and found the issue. I had misspelled the nameserver line, I wrote it as namserver.. errr... now its working... thanks guys.

IsaacKuo · 11-17-2017, 01:40 PM

I'm not sure exactly what circumstances will cause network-manager to annoyingly recreate that link. It was a problem for my machines with nfs-root (booting with / on an nfs share, not a local drive).