Policy Framework Configuration Guide - Juniper Networks

Junos 10.4 Policy Framework Configuration Guide
policy; the route is accepted or rejected and the evaluation ends, or the next policy is
evaluated.
Table 13 on page 60 summarizes the policy actions and their corresponding TRUE and
FALSE values and flow control action values. Table 14 on page 60 describes the logical
operators. For complete information about policy expression evaluation, see “How a
Policy Expression Is Evaluated” on page 62.
You must enclose a policy expression in parentheses. You can place a policy expression
anywhere in the import or export statements and in the from policy statement.
Table 13: Policy Action Conversion Values
Policy Action
Conversion Value
Flow Control Action Conversion Value
Accept
TRUE
Accept
Reject
FALSE
Reject
Next policy
TRUE
Next policy
Table 14: Policy Expression Logical Operators
Logical Operator
Policy Expression Logic
How Logical Operator Affects Policy Expression
Evaluation
&& (Logical AND)
Logical AND requires that all values must
be TRUE to produce output of TRUE.
Routing policy value of TRUE and TRUE
produces output of TRUE. Value of TRUE
and FALSE produces output of FALSE.
Value of FALSE and FALSE produces
output of FALSE.
If the first routing policy returns the value of TRUE, the next
policy is evaluated. If the first policy returns the value of
FALSE, the evaluation of the expression ends and subsequent
policies in the expression are not evaluated.
|| (Logical OR)
Logical OR requires that at least one
value must be TRUE to produce output
of TRUE.
Routing policy value of TRUE and FALSE
produces output of TRUE. Value of TRUE
and TRUE produces output of TRUE.
Value of FALSE and FALSE produces
output of FALSE.
If the first routing policy returns the value of TRUE, the
evaluation of the expression ends and subsequent policies in
the expression are not evaluated. If the first policy returns the
value of FALSE, the next policy is evaluated.
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