Set location qualifiers 编辑

The database used to implement static proximity has the location of the GSLB sites. Each location has an IP address range and up to six qualifiers for that range. The qualifiers are literal strings and are compared in a prescribed order at run time. Every location must have at least one qualifier. The qualifier labels define the meaning of the qualifiers (context), which are user defined. Citrix ADC has two built-in contexts:

Geographic context, which has the following qualifier labels:

• Qualifier 1 – “Continent”
• Qualifier 2 – “Country”
• Qualifier 3 – “State”
• Qualifier 4 – “City”
• Qualifier 5 – “ISP”
• Qualifier 6 – “Organization”

Custom entries, which have the following qualifier labels:

• Qualifier 1 – “Qualifier 1”
• Qualifier 2 – “Qualifier 2”
• Qualifier 3 – “Qualifier 3”
• Qualifier 4 – “Qualifier 4”
• Qualifier 5 – “Qualifier 5”
• Qualifier 6 – “Qualifier 6”

If the geographic context is set with no Continent qualifier, Continent is derived from Country. Even the built-in qualifier labels are based on the context, and the labels can be changed. These qualifier labels specify the locations mapped with the IP addresses used to make static proximity decisions.

To perform a static proximity-based decision, the Citrix ADC appliance compares the location attributes (qualifiers) derived from the IP address of the local DNS server resolver with the location attributes of the participating sites. If only one site matches, the appliance returns the IP address of that site. If there are multiple matches, the site selected is the result of a round robin on the matching GSLB sites. If there is no match, the site selected is a result of a round robin on all configured sites. A site that does not have any qualifiers is considered a match.

The GEO rules for location-based policy expression allow you to check wildcard matches. This feature checks whether wildcard qualifiers match any other qualifier including non-wildcard or not. The wildcard match is done by using the matchWildcardtoany attribute that is added to the set locationParameter command.

The matchWildcardtoany attribute can be set to the following values:

• Yes: Wildcard qualifiers match any other qualifiers.
• No: Wildcard qualifiers do not match non-wildcard qualifiers but match other wildcard qualifiers. The default option is No.
• Expression: Wildcard qualifiers in an expression match any qualifier in an LDNS location but wildcard qualifiers in the LDNS location do not match non-wildcard qualifiers in an expression.

Example:

add dns policy1 "CLIENT.IP.SRC.MATCHES_LOCATION(\"Continent.country *.*.*.* \“)” <action>
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