The Set up DNS page opens
in the proper sequence if you set the Enable DNS Server value to
yes on the Set up this Server page in the setup interview. It also
opens if you click
DNS on the navigation bar.
To set up the DNS server, be sure that the Enable DNS Server value is
yes. If you already configured a primary DNS server elsewhere and
synchronized to it, then the setup process advises you that the current Cisco
Network Registrar host is already configured as a
secondary or caching server, and no further DNS configuration is necessary.
Choose the configuration values you want, based on information in the
following subsections, then click
Next to activate your settings. The setup pages that follow are
for configuring forward and reverse DNS zones (including for High-Availability
DNS servers), zone distributions, and access controls.
DNS Server Role
A DNS server can be a primary or
Primary (the preset value)—Authoritative for a zone and
maintains this zone information in its database.
- Secondary—Loads a
copy of the primary server zone information. The primary notifies the secondary
about changes to its zone information and does a zone transfer to the
Caching—Caches the query results.
If the server is a primary, you can also determine if you want it to
be part of a High-Availability (HA) DNS server configuration (see
Enable High-Availability DNS
section). If the server is a secondary, you can set the access controls for the
Enable High-Availability DNS
High-Availability (HA) DNS
servers provide failover in case a server goes down. In this relationship, a
second primary server can become a hot standby that shadows the main primary
To provide HA DNS service, set the Enable High-Availability DNS value
yes. If the setup process detects an existing complex HA DNS
configuration, it notifies you that you are not allowed to configure HA DNS
from the setup interview. You are prevented from HA DNS configuration in the
setup pages if HA DNS was already configured in Advanced mode and one of the
following conditions is true:
- More than one HA DNS
server pair is configured.
- A single HA DNS pair
exists, and a main-server or backup-server value was set.
For the follow-up HA DNS configuration, see
Setting Up High-Availability DNS.
Server Logging Mode
The DNS server provides log
messages and you can set the mode for the message output. The Server Logging
Mode option has four possible values that translate into specific logging
normal-operations—Normal logging occurs.
high-performance—High-performance logging occurs.
debugging—Debug logging occurs.
customized—Prompts to configure specific log settings, then
logs only those settings.
Enable DNS Traps
Setting SNMP traps for the DNS
server provides a way of reporting whether the server is up or down, the status
of its partner communication, partner configuration, master communication and
secondary zone status. DNS traps are not enabled by default, so you have to set
this value to
yes to enable it. See
Setting Up DNS Traps
Setting Up High-Availability DNS
The Set up High-Availability DNS
page opens in the proper sequence if you set the Enable High-Availability DNS
yes, and if the DNS Server Role is set to 'primary' on the
Set up DNS Server page in the setup interview.
The preset value for Enable High-Availability DNS is
yes and the preset value for HA DNS Role is
main. The DNS Role is the role that you want this particular
machine to perform. If you change the role of the current machine to
backup, you cannot perform further failover configuration on this
machine. (A message advises you to perform the failover configuration on the
main server machine and to do an HA DNS synchronization from it.) Likewise, if
Cisco Prime Network Registrar detects a complex HA DNS configuration, it warns you and
you need to step past the HA DNS configuration setup.
The HA Partner value determines the address and access criteria for the
remote backup server. If a cluster already exists for the server, you can
choose the cluster from the Select existing cluster drop-down list. If there is
no existing cluster, you can set one up for the backup server:
- Enter the hostname or IP
address of the backup DNS server.
- Enter the access criteria
for the backup server: its administrator name and password, and SCP port number
Add Cluster to add the cluster.
Choose or enter the configuration values you want, then click
Next to activate your settings so that you can configure a DNS