Updated on 04 Mar, 2022
The Split DNS feature is related to the External DNS and Split Routing features.
By default DNS service is included on all UTunnel servers to avoid DNS leaks. When the VPN is connected, all client devices will be using the UTunnel DNS server for name resolution. But you may need to override this behavior if your organization is using an internal DNS server and if you want to resolve names on an internal/private domain. With the External DNS server option, you can let VPN devices use your own DNS server for the name resolution.
When both split routing and external DNS are enabled, the DNS server set with the LAN connection may be enforced instead of the DNS server offered by the VPN server. This will result in names on your internal/private domain not resolving when the VPN is connected. You can use the split DNS feature to override this scenario. Split DNS allows you to define your internal domain names; then the configured external DNS server will be used as the recursor for the names on the internal domains.