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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter17 Configuring Basic Settings
Configuring the DNS Server
If no master passphrase is in effect, a warning statement appears when you click Apply. Click OK or
Cancel to continue.
Step3 Check the Change the encryption master passphrase check box.
Step4 Enter the old master passphrase in the Old master passphrase field. You must provide the old master
passphrase to disable it.
Step5 Leave the New master passphrase and the Confirm master passphrase fields empty.
Step6 Click Apply.

Recovering the Master Passphrase

You cannot recover the master passphrase.
If the master passphrase is lost or unknown, you can remove it using the write erase command followed
by the reload command. These commands remove the master key and the configuration that includes the
encrypted passwords.

Feature History for the Master Passphrase

Table17-1 lists each feature change and the platform release in which it was implemented. ASDM is
backwards-compatible with multiple platform releases, so the specific ASDM release in which support
was added is not listed.
Configuring the DNS Server
Some ASA features require use of a DNS server to access external servers by domain name; for example,
the Botnet Traffic Filter feature requires a DNS server to access the dynamic database server and to
resolve entries in the static database. Other features, such as the ping or traceroute command, let you
enter a name that you want to ping or traceroute, and the ASA can resolve the name by communicating
with a DNS server. Many SSL VPN and certificate commands also support names.
Note The ASA has limited support for using the DNS server, depending on the feature. For these feature, to
resolve the server name to an IP address, you must enter the IP address manually by adding the server
name in the Configuration > Firewall > Objects > Network Object/Groups pane.
Table17-1 Feature History for the Master Passphrase
Feature Name
Platform
Releases Feature Information
Master Passphrase 8.3(1) This feature was introduced.
We introduced the following screens: Configuration >
Device Management > Advanced > Master Passphrase.
Configuration > Device Management > Device
Administration > Master Passphrase.