Flow Filter Settings


    You can configure this Options only from the NetFlow Analyzer Central Server UI by selecting as specific Collector from the drop down.

    The Flow Filter settings empower the administrator with the option to

    • Exclude ESP_App on user defined interfaces - This helps in ensuring that traffic is not double counted in case of ESP tunnels.
    • Suppress Access Control List related drops (based on destination interface being null) on user defined interfaces.
    • Suppress output interface accounting on user defined interfaces - Useful when working with WAN accelarator.
    • Apply GRE filter on the cryptomap tunnels to prevent double counting of GRE traffic. 

      Option Description
      Select edge interfaces of a cryptomap tunnel to apply ESP application filter

      One could add or modify interfaces to apply the ESP application filter. Enabling NetFlow on cryptomap tunnel interfaces double counts the ESP traffic. To prevent this please apply this filter on cryptomap tunnel interfaces. It is possible to add or modify interfaces.

      Select interfaces to apply access control traffic filter

      Access control filter drops the flow information which contains data pertaining to dropped traffic due to Access Control List. Please apply this filter to drop such flows. These flows have the destination interface as null. If any interface is selected to apply this filter, all the traffic coming from this interface with destination as null interface will be dropped.

      Select interfaces to apply output interface suppression filter

      Please select any WAN optimizer's LAN facing interfaces to suppress the incorrect out traffic ( due to compression ) reported by them. This filter stops the out traffic for any interface that is coming as a destination interface of a flow for a selected interface. When a WAN optimizer sends a flow which has source and destination interfaces as A and B respectively , if you select interface A to perform output suppression, B will not get out traffic which is not a correct traffic if reported by interface A ( since compression is happening on interface B on the WAN optimizer )

      Select edge interfaces of a cryptomap tunnel to apply GRE application filter

      Please select any cryptomap tunnel interface in which you want to apply GRE fiter. This prevents the GRE traffic getting double counted. Otherwise the cryptomap interface in which NetFlow is enabled double counts the GRE traffic.