Instruction manual

Appendix A: Policy Expressions

NetScaler 9000 Series Installation and Configuration Guide - Volume 1 A-15

NSICG60_JAN05

add filter policy filter_nongetpost –rule "method != get

&& method != post" –reqAction RESET

Policies can also use a combination of named expressions and expression

logic too. One such example is:

add expr http_port "destport == 80"

add expression excel_ppt "RES.HTTP.HEADER Content-Type

CONTAINS application/vnd.ms-excel || RES.HTTP.HEADER

Content-Type CONTAINS application/vnd.ms-powerpoint"

add cmp policy cmppol –rule "(sourceip == 10.102.0.0

–netmask 255.255.0.0 && http_port) || excel_ppt"

–resAction COMPRESS

In above examples, filter policy and compression policies use built-in actions

RESET and COMPRESS.

Expression_logic can be described by below grammar:

:= <flow-type>.<protocol>.<basic-qualifier>

<simple-expr> := <non-ip-header-qualifier> <binary-op>

:= <non-ip-header-qualifier> <unary-op>

:= <header-qualifier> <header-name> <binary-op>

:= <header-qualifier> <header-name> <unary-op>

<simple-expression> := <simple-expr>

:= <simple-expr> -length <length>

:= <simple-expr> -length <length> -offset <offset>

:= <ip-qualifier> <binary-op> <ipaddr>

:= <ip-qualifier> <binary-op> <masked-ipaddr> -netmask

<compound-expression> := <simple-expression>

:= <expression-name>