1 Configuring GSLB protocol parameters
Traffic distribution specifications
In general, DNS response selection counters are maintained per IP address, per domain name. For example, suppose you configure three GSLB sites with assigned weights. All three sites host the application www.gslb.com and sites New York and London also host ftp.gslb.com, as illustrated below.
www.gslb.com
VIP 1.1.1.1 belongs to San Jose with a weight of 50 VIP 1.1.1.2 belongs to New York with a weight of 30 VIP 1.1.1.3 belongs to London with a weight of 20
ftp.gslb.com
VIP 1.1.1.2 belongs to New York with a weight of 30 VIP 1.1.1.3 belongs to London with a weight of 20
Suppose that 10 DNS requests are made to www.gslb.com. By viewing the selection counters (using the show gslb dns zone command), you would see that San Jose is selected 5 times (50%), New York is selected 3 times (30%), and London is selected 2 times (20%).
Now suppose that 5 DNS requests are made to ftp.gslb.com. In this case, New York receives 3 requests (60%), and London receives 2 requests (40%). This is because counters are maintained per IP address per domain name.
If you consider the total site traffic for both applications, the traffic distribution is as follows: San Jose = 5 (33%); New York = 6 (40%); and London = 4 (26%). The GSLB ServerIron ADX evaluates the results of the weighted metrics with respect to a specific domain name, not an IP address alone.
Configuring weighted site metrics
To configure weighted site metrics, complete the following tasks.
1.Enable the weighted site metric.
2.Select the site for which to apply weights.
3.Configure a weight for the site.
For example, enter commands such as the following:
Syntax: [no] weighted-site
Syntax: gslb site <site name>
The <site name> can have a maximum of 16 characters.
Syntax: weight <weight>
The <weight> is a value from 0 to 100. The default value is 0.
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