Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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IP Services—IP Settings, DHCP, and DNS
DHCP Server
Configuring Dynamic DNS (DDNS)
A DNS server resolves hostnames to IP addresses. For the DNS server to
function correctly, clearly its table must include the correct IP address for
each hostname. However, a device that acts as a DHCP client might unexpect-
edly receive a new IP address, invalidating the DNS server’s hostname table.
DDNS addresses this problem by updating a DNS server whenever a client’s
IP address changes.
The Wireless Edge Services xl Module supports DDNS as part of its function
as a DHCP server. The module can either update the DNS server itself or allow
clients to do so. The DNS server itself, of course, must also support DDNS (as
specified in Request for Comments [RFC] 2136). Such a server is called a
DDNS server. In addition, if the clients will send the updates, they must also
support DDNS.
You enable and configure DDNS separately for each DHCP pool, which can
be either a network pool or a host pool. Complete these steps:
1. Select Network Setup > DHCP Server > Configuration.
2. To configure DDNS for a network pool, complete these steps and then
proceed to step 4:
a. Select one of the pools in the Network Pool section. (See “Creating a
Network Pool” on page 6-24 for instructions on creating the pool.)
b. Click the DDNS button. The Global Options screen for DDNS is dis-
played.
3. To configure DDNS for a host pool, complete these steps and then proceed
to step 4:
a. Click the Host Pool tab.
b. Select one of the pools. (See “Creating a Host Pool” on page 6-28 for
instructions on creating the pool.)
c. Click the DDNS button. The Global Options screen for DDNS is dis-
played.