4ServerIron ADX Global Server Load Balancing Guide
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Global Server Load Balancing overview
1
•IMAP4: the well-known name for p ort 143
•LDAP: the well-known name for port 389
•NNTP: the well-known name for port 119
•POP3: the well-known name for port 110
•SMTP: the well-known name for port 25
•TELNET: the well-known name for port 23
NOTE
To display the list when configuring zone information, enter the host-info <host-name> ? command,
where <host-name> is a string specifying a host name.
For other applications (applications not listed above), the ServerIron ADX does not perform a
Layer 7 heath check but still performs a Layer 3 or Layer 4 TCP or UDP health check.
You can customize the HTTP health check on an individual host basis by changing the URL string
the ServerIron ADX requests in the health check and the list of HTTP status codes the ServerIron
ADX accepts as valid responses to the health check.
GSLB example
Figure 1 shows an example of a GSLB configuration. In this example, the GSLB ServerIron ADX (a
ServerIron ADX configured for global SLB) is connected to the authoritative DNS server for a
specific domain. (You can configure the ServerIron ADX for more than one domain; this example
uses only one for simplicity.) The authoritative DNS server for brocade.com is known to other
devices as 209.157.23.87. This is a VIP configured on the GSLB ServerIron ADX for the DNS server.
FIGURE 1 Global Server Load Balancing configuration