Configuring Default DNS Servers

The device provides default DNS server addresses for IPv4 and IPv6 networks. Each IP address scheme (IPv4 and IPv6) has a primary and a secondary default DNS server. The default DNS servers ensure that applications (for example, Automatic Update feature or pinging a destination) which may need DNS lookups, run seamlessly if you haven't configured any DNS servers in the Internal DNS table and IP Interfaces table. In other words, the device uses the default DNS server as the last resort. For more information on when the device uses these default DNS servers for its default DNS fallback sequence, see Device's Default DNS Fallback Sequence.

The default IP addresses, which you can modify as described later in this section, of these default DNS servers are listed in the following table:

IP Addressing Scheme	Default Primary DNS Server	Default Secondary DNS Server
IPv4	8.8.8.8	8.8.4.4
IPv6	2001:4860:4860::8888	2001:4860:4860::8844

The device uses the default DNS servers only for specific applications, for example, SBC Configuration Wizard, CLI ping command, and Automatic Update feature. The device doesn't use the default DNS servers for call routing.

You can modify the IP addresses of the default DNS servers, as described below.

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To modify default DNS server addresses:

Open the DNS Settings page (Setup menu > IP Network tab > DNS folder > DNS Settings).

For IPv4 DNS servers:

In the 'Default Primary DNS Server IP' field, configure the IPv4 address of the default primary DNS server.

In the 'Default Secondary DNS Server IP' field, configure the IPv4 address of the default secondary DNS server.

For IPv6 DNS servers:

In the 'Default Primary DNS Server IPv6' field, configure the IPv6 address of the default primary DNS server.

In the 'Default Secondary DNS Server IPv6' field, configure the IPv6 address of the default secondary DNS server.

Click Apply.