Brocade Virtual ADX Global Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 152)

142 Brocade Virtual ADX Global Server Load Balancing Guide
53-1003245-01
Advanced GSLB configuration for IPv6
2
All of these metrics have default values but you can change the values if needed. In addition, you
can disable individual metrics or reorder them. Refer to
“Configuring GSLB policy metrics for IPv6”
on page 140.
GSLB Brocade Virtual ADX does not currently support the following GSLB policy metrics for IPv6
addresses:
• Active and passive round-trip time
• Connection load
Changing the order of GSLB for IPv6 policy metrics
You can change the order in which the GSLB Brocade Virtual ADX applies the policy metrics.
NOTE
Brocade recommends that you always use the health check as the first metric. Otherwise, it is
possible that the GSLB policy will not select a “best” choice, and thus send the DNS reply
unchanged. For example, if the first metric is geographic location, and the DNS reply contains two
sites, one in North America and the other in South America, for clients in South America the GSLB
policy favors the South American site after the first comparison. However, if that site is down, the
GSLB policy will find that none of the sites in the reply is the “best” one, and thus send the reply
unchanged.
You cannot change the position of the least response selection or round robin selection metric,
whichever is enabled. The GSLB Brocade Virtual ADX uses the least response selection or round
robin selection metric as a tie-breaker if the other comparisons do not result in selection of a “best”
site.
To change the order, specify the metrics in the desired order by entering a command such as the
following:
Virtual ADX(config)#gslb policy
Virtual ADX(config-gslb-policy)#metric-order set health-check capacity
num-session flashback
Least response selection Enabled.
The GSLB controller selects the site
ADX device that has been selected
less often than others. Not configurable.
Refer to
“Least response
selection metric” on page 157 .
Round robin selection Enabled.
When round robin selection is
enabled, the least response
selection metric is disabled. round
robin selection is an alternative to
least response selection. They are
mutually exclusive.
Like least response selection, round
robin selection is a tie breaker, used
only if two or more sites are equal
following comparison against all
other enabled metrics. Not configurable.
Refer to
“Round robin selection
metric” on page 158 .
TABLE 14 GSLB policy metrics for IPv6 (Continued)
Metric Default Configuration options