Brocade Virtual ADX Global Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 86)

76 Brocade Virtual ADX Global Server Load Balancing Guide
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Enabling DNS request logging
1
Enabling DNS request logging
You can enable logging of the following information for DNS requests assisted by the GSLB Brocade
Virtual ADX:
• Source IP address (the address of the client making the request)
• Best IP address (site address provided by the Brocade Virtual ADX)
• Host
• Zone
• Metric used
When you enable logging of this information, the Brocade Virtual ADX generates a Syslog message
for each DNS requests assisted by the Brocade Virtual ADX.
NOTE
The Brocade Virtual ADX sends the log messages only to the external Syslog servers you have
configured on the Brocade Virtual ADX. The messages do not appear in the Brocade Virtual ADX’s
Syslog buffer.
To enable logging of request information, enter the following command at the global CONFIG level
of the CLI.
Virtual ADX(config)#gslb log-dns
Syntax: [no] gslb log-dns
Here are some examples of the messages generated by this feature. In this example, client
10.1.1.21 sends four requests for www.example1.com.
20:52:02 User.Info 10.1.1.102 GSLB DNS request: src-ip = 010.001.001.021
best-ip = 010.001.001.101 Host = www Zone = example1.com Metric = health-check
20:51:54 User.Info 10.1.1.102 GSLB DNS request: src-ip = 010.001.001.021
best-ip = 010.001.001.101 Host = www Zone = example1.com Metric =
least-response
20:51:54 User.Info 10.1.1.102 GSLB DNS request: src-ip = 010.001.001.021
best-ip = 010.001.001.023 Host = www Zone = example1.com Metric =
least-response
20:51:53 User.Info 10.1.1.102 GSLB DNS request: src-ip = 010.001.001.021
best-ip = 010.001.001.022 Host = www Zone = example1.com Metric =
least-response
Each message shows the following information.
TABLE 5 GSLB request information
Field Description
User.Info The management IP address of the GSLB Brocade Virtual ADX.
src-ip The IP address of the client that sent the DNS request.
best-ip The IP address selected by the GSLB Brocade Virtual ADX as the best
site.
Host The host application requested by the client.
Zone The zone name requested by the client.
Metric The GSLB metric according to which the site was selected as the best
site.