dnsresolv.conf
I do not want network manager to add DNS servers received from DHCP to my /etc/resolv.conf.
When configuring from GUI/Connections/IPV4 and choose the method Automatic (address only) it still adds DNS servers received via DHCP.
Is it possible to do it per connection (specific ssid ?)
You can set DNS server to the /etc/resolv.conf to check that there is no firewall or another issue.
nano /etc/resolv.conf
And change your name server to 8.8.8.8
Check if there is a mismatch between the host you are trying to resolve via the VPN and the "DNS Domain" that the Cisco VPN server is sending.
To check for this, open a terminal and run:
tail -f /var/log/syslog
Then start openconnect via network manager. You'll see a whole bunch of output come through, including some lines like this:
Dec 5 12:54:31 canoe NetworkManager[1266]: Internal DNS: 10.0.20.21
Dec 5 12:54:31 canoe NetworkManager[1266]: Internal DNS: 10.10.3.32
Dec 5 12:54:31 canoe NetworkManager[1266]: DNS Domain: 'internal.example.com'
And further down you'll see
Dec 5 12:54:31 canoe dnsmasq[1871]: using nameserver 10.0.20.21#53 for domain internal.example.com
This means that the VPN server is instructing the client that the DNS servers should be used to resolve hosts within internal.example.com, such as server.internal.example.com.
In my case, I need to resolve server.example.com (and was not getting any result).
The solution for me was to go into the VPN settings and add example.com as an additional search domain:
Don't forget to disconnect VPN and then re-connect for the setting to take effect.
Best Answer
One way to stop Network Manager from adding dns-servers to
/etc/resolv.conffile is to do this:First open the nm conf file
/etc/NetworkManager/NetworkManager.conf:And add this to the
[main]section:Save and exit.