DNS Settings

Use the DNS Settings page to enable the DNS feature, configure the DNS servers and set the default domain used by the device. To configure the DNS Settings, follow these steps;

Procedure

Step 1

Click General IP Configuration > DNS > DNS Settings.

Step 2

In Basic Mode, enter the parameters:

  • Server Definition—Select one of the following options for defining the DNS server:

    • By IP Address—IP Address will be entered for DNS server.

    • Disabled—No DNS server will be defined.

  • Server IP Address—If you selected By IP Address above, enter the IP address of the DNS server.

  • Default Domain Name—Enter the DNS domain name used to complete unqualified host names. The device appends this to all non fully qualified domain names (NFQDNs) turning them into FQDNs.

    Note

    Don’t include the initial period that separates an unqualified name from the domain name (like cisco.com).

Step 3

In Advanced Mode, enter the parameters.

  • DNS—Select to designate the device as a DNS client, which can resolve DNS names into IP addresses through one or more configured DNS servers.

  • Polling Retries—Enter the number of times to send a DNS query to a DNS server until the device decides that the DNS server doesn’t exist.

  • Polling Timeout—Enter the number of seconds that the device waits for a response to a DNS query.

  • Polling Interval—Enter how often (in seconds) the device sends DNS query packets after the number of retries has been exhausted.

    • Use Default—Select to use the default value.

      This value = 2*(Polling Retries + 1)* Polling Timeout

    • User Defined—Select to enter a user-defined value.

  • Default Parameters—Enter the following default parameters:

    • Default Domain Name—Enter the DNS domain name used to complete unqualified host names. The device appends this to all non fully qualified domain names (NFQDNs) turning them into FQDNs.

      Note

      Don’t include the initial period that separates an unqualified name from the domain name (like cisco.com).

    • DHCP Domain Search List—Click Details to view the list of DNS servers configured on the device.

Step 4

Click Apply. The Running Configuration file is updated.

The DNS Server Table displays the following information for each DNS server configured:

  • DNS Server—The IP address of the DNS server.

  • Preference—Each server has a preference value, a lower value means a higher chance of being used.

  • Source—Source of the server’s IP address (static or DHCPv4 or DHCPv6)

  • Interface—Interface of the server’s IP address.

Step 5

Up to eight DNS servers can be defined. To add a DNS server, click Add.

Step 6

Enter the parameters.

  • IP Version—Select Version 6 for IPv6 or Version 4 for IPv4.

  • IPv6 Address Type—Select the IPv6 address type (if IPv6 is used). The options are:

    • Link Local—The IPv6 address uniquely identifies hosts on a single network link. A link local address has a prefix of FE80, isn’t routable, and can be used for communication only on the local network. Only one link local address is supported. If a link local address exists on the interface, this entry replaces the address in the configuration.

    • Global—The IPv6 address is a global Unicast IPV6 type that is visible and reachable from other networks.

  • Link Local Interface—If the IPv6 address type is Link Local, select the interface through which it’s received.

  • DNS Server IP Address—Enter the DNS server IP address.

  • Preference—Select a value that determines the order in which the domains are used (from low to high). This effectively determines the order in which unqualified names are completed during DNS queries.

Step 7

Click Apply. The DNS server is saved to the Running Configuration file.