Configure Basic DNS Settings

You need to configure a DNS server so that the ASA can resolve host names to IP addresses. You also must configure a DNS server to use fully qualified domain names (FQDN) network objects in access rules.

Procedure

Step 1

In the edit ASA system settings page, click DNS in the left pane.

Step 2

Uncheck the Retain existing values checkbox to configure the values for the shared ASA system settings policy.

Important

If the Retain existing values check box is selected, you can't configure the values as the fields are hidden. CDO uses the existing local values of the ASA device for this setting and doesn't inherit from the shared policy.

Step 3

In the DNS section, click to configure servers.

IP Version: Select the IP address version you want to use.
IP Address: Specify DNS server's IP address.
Interface Name: Specify the interface where the DNS lookup should be enabled.

Note	Ensure the interface name specified here is the same on the ASA devices associated with this shared system settings policy.

Step 4

Click Save.

Step 5

In the Domain name field, specify the domain name for the ASA.

The ASA appends the domain name as a suffix to unqualified names. For example, if you set the domain name to “example.com” and specify a syslog server by the unqualified name of “jupiter,” then the ASA qualifies the name to “jupiter.example.com.”

Step 6

In the DNS Lookup section, click and specify the interface name.

If you do not enable DNS lookup on an interface, then the ASA will not communicate with the DNS server on that interface. Make sure to enable DNS lookup on all interfaces that will be used to access DNS servers.

Note	To remove a configured interface, you can click the delete icon under Actions.

Step 7

Click Save.