Re: Netflow Router-aggregate Mask option

Hi,

How do you have you flow monitor and interfaces configured ?? Which
directions are you capturing records (input or output or both)??

Regards,
Max

On Sun, Jan 16, 2011 at 11:53 AM, Tom Kacprzynski <tom.kac_at_gmail.com> wrote:

> 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 - 14:10:20 ART