Monitoring GRE traffic with Netflow

luiz.alexandre.paiva · ‎05-24-2007

Hi,

I have a GRE tunnel between an 3660 and a 3725. Under this tunnel there are many routers from SP, that we not even can see.

The problem is that at Netflow it shows me only a high GRE traffic, giving me only details if using Nbar but still like that loosing all of informations available at Netflow reports (Conversations, source, etc).

So, does anybody knows what should be configured at routers to enable netflow detailed informations of GRE tunnel?

Rds,

Alex

tkaye · ‎05-24-2007

Can you supply a sample configuration.

I assume you have setup the following

Global

ip flow-cache timeout active 1

ip flow-cache timeout inactive 15

!

ip flow-export source FastEthernet0

ip flow-export version 5

ip flow-export destination net.flow.host.server 9996

!

Per interface

ip route-cache flow

Sorry to state the obvious

luiz.alexandre.paiva · ‎05-25-2007

ip flow-cache timeout active 5

ip flow-export source Loopback0

ip flow-export version 5

ip flow-export destination [Server IP] 9996

interface Tunnel0

description tunnel vers rct2sin2

bandwidth 27000

ip address x.x.x.x x.x.x.x

ip mtu 1472

ip nbar protocol-discovery

ip route-cache flow

ip tcp adjust-mss 1432

load-interval 30

These are my confiurations and the router is a 3660.

Rds,

Alex