Cfrtjryk

I am having an issue where DHCP (I though as I read in other similar topics) is clearing the /etc/resolv.conf file on each boot. I am not sure about how to deal with this since the post I have found (1, 2 and some others) are for Debian based distros or other but not Fedora.

This is the output of ifcfg-enp0s31f6 so for sure is DHCP:

cat /etc/sysconfig/network-scripts/ifcfg-enp0s31f6 

HWADDR=C8:5B:76:1A:8E:55

TYPE=Ethernet

DEFROUTE=yes

IPV4_FAILURE_FATAL=no

IPV6INIT=no

IPV6_AUTOCONF=no

IPV6_DEFROUTE=no

IPV6_FAILURE_FATAL=no

IPV6_ADDR_GEN_MODE=stable-privacy

NAME=enp0s31f6

UUID=0af812a3-ac8e-32a0-887d-10884872d6c7

ONBOOT=yes

IPV6_PEERDNS=no

IPV6_PEERROUTES=no

BOOTPROTO=dhcp

PEERDNS=yes

PEERROUTES=yes

In the other side I don't know if Network Manager is doing something else around this.

Update: Content of NetworkManager.conf (I have removed the comments since are useless)

$ cat /etc/NetworkManager/NetworkManager.conf 

[main]

#plugins=ifcfg-rh,ibft

dns=none



[logging]

#domains=ALL

Can I get some help with this? It's annonying be setting up the file once and once on every reboot.

UPDATE 2

After a month I'm still having the same issue where file gets deleted by "something".

Here is the steps I did follow in order to make a fresh test:

• Reboot the PC


• 
  

  After PC gets restarted open a terminal and try to ping Google servers of course without success:

  
  
  

  $ ping google.com
  
  ping: google.com: Name or service not known
  
  

  
  


• 
  

  Check the network configuration were all seems to be fine:

  
  
  

  $ cat /etc/sysconfig/network-scripts/ifcfg-enp0s31f6 
  
  NAME=enp0s31f6
  
  ONBOOT=yes
  
  HWADDR=C8:5B:76:1A:8E:55
  
  MACADDR=C8:5B:76:1A:8E:55
  
  UUID=0af812a3-ac8e-32a0-887d-10884872d6c7
  
  BOOTPROTO=static
  
  PEERDNS=no
  
  DNS1=8.8.8.8
  
  DNS2=8.8.4.4
  
  DNS3=192.168.1.10
  
  NM_CONTROLLED=yes
  
  IPADDR=192.168.1.66
  
  NETMASK=255.255.255.0
  
  BROADCAST=192.168.1.255
  
  GATEWAY=192.168.1.1
  
  TYPE=Ethernet
  
  DEFROUTE=yes
  
  IPV4_FAILURE_FATAL=no
  
  IPV6INIT=no
  
  

  
  


• 
  

  Restart the network service:

  
  
  

  $ sudo service network restart
  
  [sudo] password for <current_user>: 
  
  Restarting network (via systemctl):                        [  OK  ]
  
  

  
  


• 
  

  Try to ping Google servers again, with no success:

  
  
  

  $ ping google.com
  
  ping: google.com: Name or service not known
  
  

  
  


• 
  

  Check for file /etc/resolv.conf:

  
  
  

  $ cat /etc/resolv.conf 
  
  cat: /etc/resolv.conf: No such file or directory
  
  

  
  



• File doesn't exists anymore - and this is the problem something is deleting it on every reboot



• 
  

  Create the file and add the content of DNS:

  
  
  

  $ sudo nano /etc/resolv.conf 
  
  

  
  


• 
  

  Ping Google servers this time with success:

  
  
  

  $ ping google.com
  
  PING google.com (216.58.192.110) 56(84) bytes of data.
  
  64 bytes from mia07s35-in-f110.1e100.net (216.58.192.110): icmp_seq=1 ttl=57 time=3.87 ms
  
  

  
  

Any ideas in what could be happening here?

In my experience, /etc/resolv.conf gets regenerated on boot, so any manual changes to it get reset.

To work around this, you can create /etc/resolv.conf.head (or .tail depending on which end of the file you want to add to) and insert the custom settings you want in there (usually nameserver changes). Then the contents of that file gets added automatically when /etc/resolv.conf is generated by NetworkManager (or whichever service is in charge of the file on your system).

I think you were right on track.

It's working for me now, but I didn't do the:

dns=none

on the:

/etc/sysconfig/network-scripts/ifcfg-enp0s31f6

After I restarted the network manager, it automatically created the resolv:

sudo service NetworkManager restart

I rebooted and it still worked.

"Have you tried setting your resolv.conf file to have immutability after putting whatever content you want?."

pretty sure this keeps the /etc/dhcp/dhclient.conf from doing its job and your DNS never resolves anyway. At best this is frustrating and at worst freezes things up as your computer continuously tries to run that file and establish a connection. I think the key is in editing "/etc/dhcp/dhclient.conf" instead of resolv.conf directly, as that is the file that writes to resolv.conf on reboot.

Probably NetworkManager is configuring resolve.conf. if you don't want that, change rc-manager setting in NetworkManager.conf. See man NetworkManager.conf.

To prevent resolv.conf to be update at boot time, you should make the following changes:

Change PEERDNS=yes to PEERDNS=no

PEERDNS=no

This will prevent network service from updating /etc/resolv.conf with the DNS servers received from a DHCP server.

mentioned on @Ipor Sircer comment's