Brocade Communications Systems ServerIron ADX 12.4.00 - Manual (Page 142)

130 ServerIron ADX Global Server Load Balancing Guide
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Geographic region for a prefix
1
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.
Configuring a geographic prefix
Using the geo-prefix command, you can configure the geographic location of an IP address prefix,
or override an existing geographic region for an IP address prefix by configuring a new one.
You can assign one of the following geographic locations to an IP address prefix:
• North America
• South America
• Europe
• Asia
• Africa
For IPv4:
GSLB-ServerIronADX# configure terminal

GSLB-ServerIronADX(config)# gslb policy

GSLB-ServerIronADX(config-gslb-policy)# geo-prefix 24.192.0.0/24 europe

GSLB-ServerIronADX(config-gslb-policy)# end
These commands create a geographic prefix entry with IPv4 address 24.192.0.0, prefix length 24,
and geographic region Europe
For IPv6:
GSLB-ServerIronADX# configure terminal

GSLB-ServerIronADX(config)# gslb policy

GSLB-ServerIronADX(config-gslb-policy)# geo-prefix 2001.db8::/64 asia

GSLB-ServerIronADX(config-gslb-policy)# end
These commands create a geographic prefix entry with IPv6 address 2001.db8::, prefix length 64,
and geographic region Asia.