• SonicOS and SonicOSX 7
• Configuring DNS Settings
  • Configuring DNS for IPv4
    • Specifying which DNS Servers are Used
    • Enabling Proxy of Split DNS Servers
    • DNS Rebinding Attack Prevention
    • DNS Rebinding and Cache Lookup
    • Enabling DNS Host Name Lookup over TCP for FQDN
    • DNS Cache Lookup
  • Configuring DNS for IPv6
  • Configuring Domain-Specific DNS Servers for Split DNS
    • About Split DNS
      • About Per-Partition DNS Servers and Split DNS
    • Adding a Split DNS Server
    • Editing Split DNS Entries
    • Deleting Split DNS Entries
• Configuring Dynamic DNS
  • About Dynamic DNS
    • Supported DDNS Providers
  • Dynamic DNS Profiles
    • Configuring Dynamic DNS Profiles
    • Editing Dynamic DNS Profiles
    • Deleting Dynamic DNS Profiles
• Configuring DNS Proxy Settings
  • About DNS Proxy
    • Supported Interfaces
    • DNS Server Liveness Detection and Failover
    • DNS Cache
    • High Availability Stateful Synchronization of DNS Cache
    • DHCP Server
  • Enabling Log Settings
  • Monitoring Packets
  • Configuring DNS Proxy Settings
    • Enabling DNS Proxy
    • Configuring DNS Proxy Settings
    • Deleting Static DNS Cache Entries
    • Viewing DNS Proxy Cache Objects
    • Flushing Dynamic DNS Cache Entries
• Configuring DNS Security
  • About DNS Sinkholes
  • Configuring DNS Security Settings
  • Deleting Entries in the Lists
  • Configuring DNS Tunnel Detection
    • Configuring DNS Tunneling Detection
    • Viewing Detected Suspicious Clients
    • Creating DNS Tunnel Detection White Lists
    • Deleting DNS Tunnel Detection White List Entries
• SonicWall Support
  • About This Document

Specifying which DNS Servers are Used

Regardless of the IP version, you can specify how SonicOS/X selects the DNS servers. The method is the same for both IP versions.

To specify which DNS servers are used

1. Navigate to Network | DNS > Settings.
2. In the IPv4 DNS Settings or IPv6 DNS Settings section (depending on which version you chose), 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 IPv4/IPv6 DNS Settings Dynamically from WAN Zone. This is the default. The IP address(es) are populated into the DNS Server fields automatically.

3. If you selected IPv6, and want to use ONLY IPv6 servers, select Prefer IPv6 DNS Servers. This option is not selected by default.

   SonicOS/X 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.