Instruction manual

Appendix A: Policy Expressions
A-6 NetScaler 9000 Series Installation and Configuration Guide - Volume 1
NSICG60_JAN05
add policy expression vpnport "REQ.TCP.DESTPORT"
A.1.1.2 Understanding Operands
An operand defines the values for the corresponding qualifiers. Consider the
following example.
add expression exp_gif "url == *gif"
The “*” wildcard character can be used to match the string within the
specified qualifier. This character can appear only once within the string. By
using wildcard characters, the user can restrict the processing of a string. For
example, in a string “/*gif” and “gif” will match on the first instance of gif,
but not at the last instance of gif if there is more than one gif in the string.
This can be of particular importance when using rule based persistence, so the
user has to carefully craft the strings that should be matched.
A.1.1.3 Understanding Operators
An operator identifies an operation an object performs on its operands.
Particular qualifiers will limit what operators are available. Table I-1 provides
a brief description of each operator.
Table 0-1. Operators
Operator Description
==, !=, EQ, NEQ
Note: With == or
EQ operators,
These operators test for exact matches, but in doing so, are
case sensitive. These operators are useful for creating
permissions to allow particular strings when they must
meet an exact syntax, but exclude other strings.
"cmd.exe" is NOT EQUAL to "cMd.exe".
GT This operator is used for numerical comparisons and is
used on the length of the URLs and query strings.
CONTAINS,
NOTCONTAINS
These operator perform check against the specified
qualifier to determine if the specified string is contained in
the qualifier. These operator are not case sensitive.