Netflow Router-aggregate Mask option

Hello
I am a little bit confused about the mask feature in netflow
router-aggregate. I was under the impression that when you configure the
minimal mask that it would aggregate for a prefix length that's smaller or
larger then the routing table's prefix. For example:

I have a few routes that are /16:

Rack1R4#sh ip route 30.0.0.0 255.0.0.0 longer-prefixes
     30.0.0.0/16 is subnetted, 4 subnets
R 30.2.0.0 [120/1] via 204.12.1.254, 00:00:02, GigabitEthernet0/0
R 30.3.0.0 [120/1] via 204.12.1.254, 00:00:02, GigabitEthernet0/0
R 30.0.0.0 [120/1] via 204.12.1.254, 00:00:02, GigabitEthernet0/0
R 30.1.0.0 [120/1] via 204.12.1.254, 00:00:02, GigabitEthernet0/0

I would like to configure netflow to aggregate based on a destination
prefix mask of /8, so I configure the router:

ip flow-aggregation cache destination-prefix
 mask destination minimum 8
 enabled

I ping few of the hosts in the 30.x.x.x subnet and this is what aggregation
I get:

Rack1R4#sh ip cache verbose flow aggregation destination-prefix
...
Minimum destination mask is configured to /8

Dst If Dst Prefix Msk AS Flows Pkts B/Pk Active
Gi0/1 155.1.146.0 /24 0 1 5 100 0.0
Gi0/0 30.1.0.0 * /16* 0 3 15 100 23.2
Gi0/0 30.2.0.0 * /16* 0 1 5 100 0.0

...as you can see it's NOT aggregating it to the /8 as I set it in the
aggregation cache with minimal destination mask but it's still using the
/16 as it's in the routing table.

Anyway to configure this with aggregate for /8?

Thank you in advance for any help.

TK

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Received on Sun Jan 16 2011 - 11:53:07 ART