Brocade Communications Systems ServerIron ADX 12.4.00 - Manual (Page 228)

216 ServerIron ADX Global Server Load Balancing Guide
53-1002437-01
Advanced GSLB configuration for IPv6
2
ServerIronADX# configure terminal

ServerIronADX(config)# gslb dns zone company.com

ServerIronADX(config-gslb-dns-company.com)# host-info www http

ServerIronADX(config-gslb-dns-company.com)# host-info www ssl

ServerIronADX(config-gslb-dns-company.com)# host-info www http track-port

ServerIronADX(config-gslb-dns-company.com)# end
Geographic location metric
ServerIron ADX GSLB policies use a number of metrics, including the geographic location of a
server, to evaluate the server IP addresses in an IP list.
Once you configure a geographic region for an IP address prefix, the GSLB ServerIron ADX
determines the geographic region of a server in the following ways:
• For a real address, the geographic region is based on the IP address. If you configure a
geographic prefix that matches the real server IP address, the device obtains the geographic
location of the real server from the geographic prefix entry that you configure.
• For a virtual IP address (VIP), the geographic region is based on the management IP address of
the site ServerIron ADX on which the VIP is configured. If you configure a geographic prefix that
matches the management IP address of the site ServerIron ADX on which the VIP is configured,
the device obtains the geographic location of the VIP from the geographic prefix entry that you
configure.
• If the management IP address of the remote ServerIron ADX at that site is not indicative of the
geographic location, use the geo-location command to specify the region of the GSLB site. For
more information about this command, see the
“Specifying site locations” on page 217. For
example, if the management IP address is in a private subnet, the address is not indicative of
the ServerIron ADX’s geographic location. If you specify the region for the GSLB site, the GSLB
ServerIron ADX uses the region you specify instead of the region of the ServerIron ADX’s
management IP address.
• If you configure a geographic prefix entry that matches the management IP address of the
remote ServerIron ADX and also specify a geographic location for the GSLB site where the
remote ServerIron ADX resides, then the geographic location configured for the GSLB site
takes precedence over the one defined in the user-configured geographic prefix entry. For
example, the geographic region for a VIP configured on the remote ServerIron ADX will be
obtained from the geographic location configured for the GSLB site where the remote
ServerIron ADX resides instead of the geographic prefix entry that matches the management IP
address of the remote ServerIron ADX.
The GSLB ServerIron ADX determines the geographic location of the client as follows: For each
client query, the GSLB ServerIron ADX determines the geographic location from which the client
query came based on its IP address.
• If the IP address prefix of a user-configured geographic prefix entry matches that of the client,
then the geographic location of the client will be as specified in the user-configured geographic
prefix entry.
• If multiple server IP addresses compare equally based on the GSLB metrics above the
geographic metric in the GSLB policy, then the GSLB ServerIron ADX prefers server IP
addresses within the same geographic region as the client query.