Ignore DNS Server
How to ignore DNS servers issued by the OpenVPN server
Sometimes if you use an internal corporate DNS server to resolve internal host names, it is desirable not to change the DNS settings when connecting to a VPN
For the client to ignore the DNS assigned by the server but still receive the correct route list, add the option to the configuration file:
pull-filter ignore "dhcp-option DNS"
After that it is necessary to reconnect.