High ESP traffic over ipsec tunnel

[zineeddine.b]

Hi,

I have two sites connected over an IPSec tunnel, through two Cisco 2911 routers.

On site A, I've set up PRTG to collect Netflow traffic from the two routers.

On router A I applied the original NetFlow configuration

On router B I set up a flexible NetFlow configuration, to allow flow exportation over the IPSec tunnel to the PRTG collector in Site A.

The problem is that I see in PRTG a high ESP traffic (> 90%) consuming a lot of bandwidth. But when I disable Netflow on router B, this traffic dropdown under 1 %!

Did I miss something when setting up the Netflow configuration?

Thanks.

[Richard Burts]

Perhaps there are aspects of this issue that I am not understanding. But it seems logical that when you enable NetFlow on router B and send the NetFlow traffic over the ipsec encrypted tunnel that it would increase the amount of ESP traffic. And that when you disable NetFlow on router B that it would decrease the amount of traffic being sent over the ipsec encrypted tunnel. If there is something I am not understanding please provide clarification.

HTH

Rick