Brocade Communications Systems 12.4.00 manual Displaying detailed DNS information

1 Displaying GSLB information

TABLE 11 GSLB zone and host application information (Continued)

This field...	Displays...
Location	The geographic location of the server. The location is based on the IP
	address and can be one of the following:
	•	ASIA
	•	EUROPE
	• N-AM: North America
	• S-AM: South America
	The GSLB ServerIron ADX can use this information when comparing the
	servers in order to select the “best” ones for the client. The GSLB
	ServerIron ADX prefers servers within the client’s geographic region over
	servers in other geographic regions.
FlashBack Delay (x100us)	The round-trip time for a health check sent by the GSLB ServerIron ADX
	to the host application on the server.
	The GSLB ServerIron ADX can use this information when comparing the
	servers in order to select the “best” ones for the client. The GSLB
	ServerIron ADX prefers servers with lower round-trip times to those with
	higher round-trip times.
	The value in the TCP column indicates the round-trip time of the Layer 4
	health check to the TCP port.
	The value in the App column indicates the round-trip time for the Layer 7
	health check.
	NOTE: A single value is displayed even if the zone has multiple host
		applications. If the FlashBack values (round-trip times) differ, the
		slowest times are displayed.
DNS resp. selection counters Count	The number of times the GSLB ServerIron ADX has selected this server
	as the “best” server and thus placed the server’s IP address at the top of
	the list in DNS replies.
DNS resp. selection percentage (%)	The percentage of times the GSLB ServerIron ADX has selected this
	server as the “best” server and thus placed the server’s IP address at
	the top of the list in DNS replies.

Displaying detailed DNS information

You can display all the information displayed by the show gslb dns zone command, plus information about the site and the ServerIron ADX on which a VIP is configured, by entering the show gslb dns detail command.

This command is especially useful for sites that are configured for Symmetric Server Load Balancing. For information about this load balancing feature, see High Availability.

This example assumes that the ServerIron ADXs at the sunnyvale site are each configured with two VIPs for the “www” host and two VIPs for the “ftp“ host in the brocade.com domain:

•VIPs 209.157.22.100 and 209.157.22.101 are configured on both ServerIron ADXs for the “www” host.

•VIPs 209.157.22.102 and 209.157.22.103 are configured on both ServerIron ADXs for the “ftp” host.

The same VIPs are configured on both ServerIron ADXs, but only one of the ServerIron ADXs is actively load balancing for a particular VIP. The other ServerIron ADX is the standby for that VIP and assumes load balancing duties for the VIP only if the other ServerIron ADX becomes unavailable. The default active ServerIron ADX for a particular VIP is determined by the priority you assign to the VIP when you are configuring Symmetric SLB.

172	ServerIron ADX Global Server Load Balancing Guide
	53-1002437-01