Cisco ASA 5505 - Manual (Page 357)

12-3
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter 12 Configuring Dynamic DNS
Configuration Examples for DDNS
In general, the DHCP server maintains DNS PTR RRs on behalf of clients. Clients may be configured
to perform all desired DNS updates. The server may be configured to honor these updates or not. To
update the PTR RR, the DHCP server must know the FQDN of the client. The client provides an FQDN
to the server using a DHCP option called Client FQDN.
Configuration Examples for DDNS
The following examples present five common scenarios:
• Example 1: Client Updates Both A and PTR RRs for Static IP Addresses, page 12-3
• Example 2: Client Updates Both A and PTR RRs; DHCP Server Honors Client Update Request;
FQDN Provided Through Configuration, page 12-3
• Example 3: Client Includes FQDN Option Instructing Server Not to Update Either RR; Server
Overrides Client and Updates Both RRs., page 12-4
• Example 4: Client Asks Server To Perform Both Updates; Server Configured to Update PTR RR
Only; Honors Client Request and Updates Both A and PTR RR, page 12-5
• Example 5: Client Updates A RR; Server Updates PTR RR, page 12-5
Example 1: Client Updates Both A and PTR RRs for Static IP Addresses
The following example shows how to configure the client to request that it update both A and PTR
resource records for static IP addresses.
To configure this scenario, perform the following steps:
Step 1 To define a DDNS update method called ddns-2 that requests that the client update both the A RR and
PTR RR, enter the following commands:
hostname(config)# ddns update method ddns-2
hostname(DDNS-update-method)# ddns both
Step 2 To associate the method ddns-2 with the eth1 interface, enter the following commands:
hostname(DDNS-update-method)# interface eth1
hostname(config-if)# ddns update ddns-2
hostname(config-if)# ddns update hostname asa.example.com
Step 3 To configure a static IP address for eth1, enter the following command:
hostname(config-if)# ip address 10.0.0.40 255.255.255.0
Example 2: Client Updates Both A and PTR RRs; DHCP Server Honors Client
Update Request; FQDN Provided Through Configuration
The following example shows how to configure the DHCP client to request that it update both the A and
PTR RRs, and the DHCP server to honor these requests.
To configure this scenario, perform the following steps: