Canonical name (CNAME) handling is performed in a system configured for
global server load balancing (GSLB), which orders IP addresses into a
list based on a set of performance metrics. When the GSLB switch receives
a reply from an authoritative DNS server, the GSLB switch scans the reply
for CNAME records. If a CNAME record is detected and it points to a host
name configured for GSLB, then a GSLB algorithm is applied to the reply.
This involves identifying the host name (pointed to by the CNAME record)
in the reply and applying the metrics to the list of returned IP
addresses corresponding to that host name, to reorder the list to place
the "best" IP address at the top. If the CNAME record in the reply points
to a host name that is not configured for GSLB, then the GSLB sends the
reply unaltered to the inquiring client.