Brocade Communications Systems IP250 GSLB policy management

Brocade Network Advisor IP User Manual 925
53-1003056-01
GSLB policy management 30
GSLB policy management
A GSLB policy allows a GSLB ServerIron ADX product to evaluate each IP address in a DNS reply,
based on defined criteria called metrics. The GSLB ServerIron ADX product can reorder the list of
addresses and place the IP address for the best site at the top of the list.
Creating a GSLB policy
To create a GSLB policy, perform the following steps.
1. Select Configure > Application Delivery > GSLB.
2. Click the Policy Configuration tab.
The Policy Configuration tab is displayed by default when you first launch GSLB Manager. The
tab shows the name of the GSLB policies that have already been created in the Management
application, and the Management application users who created them. The policy name and
the user who created it uniquely identifies the GSLB policy.
3. Click Add to create a new GSLB poli cy.
The Policy Configuration dialog box, shown in Figure 377, displays.
There are two tabs on the Policy Configuration dialog box:
•Metrics tab - The GSLB ServerIron ADX product evaluates each IP address in the DNS reply
based on the metrics order. Based on the results, the GSLB ServerIron ADX product can
reorder the list to place the IP address for the best site on the top of the list.
•Prefix tab - The GSLB ServerIron ADX product keeps a list of prefixes in its cache that
contains round-trip time (RTT) information. RTT is the amount of time it takes for a remote
site to initiate a TCP connection from the client plus the amount of time until the remote
site receives the client acknowledgment of the connection request.
When the GSLB ServerIron ADX product receives RTT information, the IP address of the
client is compared to the prefixes in the cache. If the address fits within the network of one
of the prefixes, the GSLB ServerIron ADX product stores the RTT information for that site
under the prefix entry.