To add in the search suffix of your internal DNS domain, just add the domain name after the DNS IP in the client config under [Interface]. See below:
DNS = 192.168.x.x, my.internal.domain
To add in the search suffix of your internal DNS domain, just add the domain name after the DNS IP in the client config under [Interface]. See below:
DNS = 192.168.x.x, my.internal.domain