netflow support on NM-16ESW

[andrew.burns]

Hi,

I need netflow on a bunch of networks, and the cheapest way seems to be putting a NM-16ESW in a 2811 (or whatever). However, I can't find any docs that say that the NM-16ESW has the hardware support for netflow so maybe someone has this combo and can confirm/deny as appropriate?

many thanks,

Andrew.

[wiluszm]

Andrew,

I just setup a 2811 with a 16ESW in it today. When I'm in the office tomorrow I will see if I can do port-level netflow on the fax/x ports.

-Mike

https://cs-mars.blogspot.com

[wiluszm]

Andrew,

I checked today on my 2811 and netflow cannot be attached to any of the interfaces on the switching card. I had a feeling it wouldn not work as netflows can only be polled off of L3 interfaces... not the L2 ones on the card. Here's the output of all available "ip" commands for a L2 port on the card:

MPLS-TEST(config-if)#ip ?

Interface IP configuration subcommands:

access-group Specify access control for packets

address Set the IP address of an interface

ddns Configure dynamic DNS

dhcp Configure DHCP parameters for this interface

header-compression IPHC options

rsvp RSVP Interface Commands

rtp RTP parameters

vrf VPN Routing/Forwarding parameters on the interface

Hope this helped!

-Mike

http://cs-mars.blogspot.com

[andrew.burns]

Hi Mike,

Could you try a "no switchport" on the ethernet interface first, to turn the interface into a routed port? (Then do a ip route-cache ?)

The other thing I'd like to try (if netflow isn't supported directly on the interface) is to create a vlan, assign that vlan to the switchport and then do a ip route-cache ? under the vlan.

hugely appreciated!!

Andrew.

[wiluszm · Accepted solution]

Andrew,

Here you go... switching it to an L3 port works:

MPLS-TEST(config)#int fa1/1

MPLS-TEST(config-if)#no switchport

MPLS-TEST(config-if)#ip route-cache ?

cef Enable Cisco Express Forwarding

flow Enable Flow fast-switching cache

policy Enable fast-switching policy cache for outgoing packets

same-interface Enable fast-switching on the same interface

As for the VLAN...works attaching it to the vlan and then assiging a port to that vlan:

MPLS-TEST(config)#int vlan 250

MPLS-TEST(config-if)#ip route-cache ?

cef Enable Cisco Express Forwarding

flow Enable Flow fast-switching cache

policy Enable fast-switching policy cache for outgoing packets

same-interface Enable fast-switching on the same interface

MPLS-TEST(config-if)#ip route-cache flow

MPLS-TEST(config-if)#int fa1/8

MPLS-TEST(config-if)#switchport access vlan 250

MPLS-TEST(config-if)#

Hope this helped. Let me know if there's anything else you want to check out.

-Mike

http://cs-mars.blogspot.com

[andrew.burns]

fantastic - thanks for the help.

Andrew.