How to Define Filters in the IPQoS Configuration File

The next procedure shows how to define filters for a class in the IPQoS configuration file. The procedure assumes that you have already begun the file and have defined classes. The steps continue building the /var/ipqos/Goldweb.qos file that is introduced in How to Begin the IPQoS Configuration File and Define Traffic Classes.

As you create the IPQoS configuration file, be very careful to start and end each class clause and filter clause with curly braces ({ }). For an example of the use of braces, use Example 3–1.

1. Open the IPQoS configuration file, and locate the end of the last class that you defined.

   For example, on the IPQoS-enabled server Goldweb you would start after the following class clause in /var/ipqos/Goldweb.qos.

   class { name video next_action markEF enable_stats FALSE }

2. Define a filter clause to select outgoing traffic from the IPQoS system.

   filter { name webout sport 80 direction LOCAL_OUT class goldweb }

   Entry	Description
   name webout	Gives the name webout to the filter
   sport 80	Selects traffic with a source port of 80, the well-known port for HTTP (Web) traffic
   direction LOCAL_OUT	Further selects traffic that is outgoing from the local system
   class goldweb	Identifies the class to which the filter belongs, in this instance, class goldweb

   For syntactical and detailed information about the filter clause in the IPQoS configuration file, refer to Filter Clause.

3. Define a filter clause to select streaming video traffic on the IPQoS system.

   filter { name videoout sport videosrv direction LOCAL_OUT class video }

   Entry	Description
   name videoout	Gives the name videoout to the filter
   sport videosrv	Selects traffic with a source port of videosrv, a previously defined port for the streaming video application on this system
   direction LOCAL_OUT	Further selects traffic that is outgoing from the local system
   class video	Identifies the class to which the filter belongs, in this instance, class video

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