I'm using an OpenVPN server running on a router installed with DD-WRT and I'm using it to route all traffic through the VPN server. I'm connecting to it from several devices: Windows laptop, android devices and linux machines. The problem I have now is recent and previously everything worked fine. This problem happens only on the client machines with linux (ubuntu 16.04). The ubuntu client doesn't get the DNS server addresses automatically. After some research, I've found out that I should add the following to the end of the client config:
script-security 2 up /etc/openvpn/update-resolv-conf down /etc/openvpn/update-resolv-conf
This didn't help so I've added also:
dhcp-option DNS a.b.c.d dhcp-option DNS e.f.g.h
The IP's are taken from the router and it makes things working. Until now it was enough to have "redirect-gateway def1" in the client config.
I don't like this solution of adding the "dhcp-option DNS" commands because I have to watch for any changes of the DNS server. Is there any way to get rid of adding "dhcp-option DNS" option?