The DNS6 section allows you to configure DNS settings for IPV6 DNS servers.
Selecting Automatic for the mode uses information provided by the current WAN connection to set the DNS6 server settings automatically.
Selecting Static for the mode requires that you manually specify the DNS6 server IP addresses. The DNS server settings will be pre-populated with public DNS6 server IP addresses. You can override the IP address with any other DNS6 server IP address of your choice.