Specifying which DNS Servers are Used

Regardless of the IP version, you can specify how SonicOS selects the DNS servers.

To specify which DNS servers are used

1. Navigate to Network | DNS > Settings.
2. In the IPv6 DNS Settings, select one of the following:
   • To manually specify the DNS servers:
     1. Select Specify DNS Servers Manually.
     2. Enter up to three IP addresses into the DNS Server # fields.
   • To use the DNS Settings configured for the WAN zone, select Inherit DNS Settings Dynamically from WAN Zone. This is the default. The IP address(es) are populated into the DNS Server fields automatically.
3. Select Prefer IPv6 DNS Servers to use IPv6 servers only. This option is not selected by default.

   SonicOS DNS supports these server types:

   • DNS_SYSTEM_BEHAVIOR – the system default behavior, which depends on the setting of this option.
   • DNS_PREFER_V4_DNSSERVER – IPv4 DNS servers preferred unless there is a failure, then IPv6 DNS servers are requested.
   • DNS_PREFER_V6_DNSSERVER: – IPv6 DNS servers preferred unless there is a failure, then IPv4 DNS servers are requested.

   Select this option only if you have configured the IPv6 DNS server correctly.

4. Click Accept to save your changes.