Example: NetFlow Version 8

The following example shows how to configure a destination prefix aggregation cache with a size of 2046, an inactive timeout of 200 seconds, an active timeout of 45 minutes, an export destination IP address of 10.42.42.1, and a destination port of 9992:

Router(config)# ip flow-aggregation cache destination-prefix
Router(config-flow-cache)# cache entries 2046
Router(config-flow-cache)# cache timeout inactive 200
Router(config-flow-cache)# cache timeout active 45
Router(config-flow-cache)# export destination 10.42.42.1 9992
Router(config-flow-cache)# enabled

As opposed to the main cache, the export of the flow records from an aggregation cache must be enabled specifically.

The output of show ip flow export displays the router-based aggregation configuration:

Router# show ip flow export
   ...
  Cache for destination-prefix aggregation:
    Exporting flows to 10.42.42.1 (9992)
    Exporting using source IP address 192.2.1.5
   ...

The show ip cache verbose flow aggregation aggregation-scheme command, which is quite similar to show ip cache verbose flow for the main cache, displays the content of the aggregation scheme. Furthermore, it shows the number of active flows, the configured timeout, and so on:

Router# show ip cache verbose flow aggregation destination-prefix
IP Flow Switching Cache, 135048 bytes
  2 active, 2044 inactive, 4 added
  924 ager polls, 0 flow alloc failures
  Active flows timeout in 45 minutes
  Inactive flows timeout in 200 seconds
IP Sub Flow Cache, 8968 bytes
  4 active, 507 inactive, 4 added, 4 added to flow
  0 alloc failures, 0 force free
  1 chunk, 1 chunk added

Dst If         Dst Prefix      Msk  AS    Flows  Pkts B/Pk  Active
Se0/2           10.48.71.0      /24  0       24   849    68   327.5
Fa0/1           192.1.1.104     /30  0        1     5   100     0.1