Netflow for 7600 series

akusuma1 · ‎05-01-2008

Hi Expert,

I am newbie in this area.

1. We want to use Netflow to monitor MPLS network, is there any specific document for 7600 platform ?

2.Is there any effect on CPU load, interface etc ?

3. Can Netflow monitor specific vlan, vrf or multilink instead of interface ?

Thanks is advance.

vmiller · ‎05-01-2008

Is it a public or private MPLS network?

If its public, you can just get data from the CE routers.

CPU load is minimal. Depends on how often you pull flows.

There are some issues with monitoring VRF's.

Netflow is not real product specific, shoulnt be an issue

akusuma1 · ‎05-01-2008

It is private network. Thank you for your info.

bvsnarayana03 · ‎05-01-2008

Load on cpu is minimal.

There are some layer 2 commands for vlan monitoring. will post them once i find.

u may want to refer this link:

http://www.cisco.com/en/US/docs/ios/12_1/switch/configuration/guide/xcdnfc.html

akusuma1 · ‎05-01-2008

Hi,

Please send me if you have the documents especially for VLAN and VRF monitoring.

Thanks.

michaelchoo · ‎05-01-2008

Hmmmm.... If I remember correctly, I don't think NetFlow supports MPLS. I admit I've never used NetFlow before, but from what I've read and heard, NetFlow only works with IP traffic, while in MPLS the IP datagram is encapsulated in an MPLS packet, which NetFlow is still having problems with. Unless, of course, Cisco has "fixed" this limitation...

michaelchoo · ‎05-01-2008

... I was too quick on the "Post" button...

As far as load goes, as with any feature, you want to make sure that your CPU utilisation is not too high before you enable NetFlow. From talking to Cisco in the past, I remember they mentioned that NetFlow could potentially burden the CPU a bit especially if there is a very large amount of network traffic that it has to "account" for.

akusuma1 · ‎05-01-2008

Thank you. For CPU load is average 20-30% so we believe it still capable to run Netflow. We also want to short the pull time and cache entries. Anyone want to confirm if Netflow can capture MPLS traffic ?

michaelchoo · ‎05-04-2008

I did a quick search on Cisco's Feature Navigator. Turns out there is MPLS-aware NetFlow. On Cisco 7600 with Sup 720/MSFC3, this feature is available on the following feature sets:

- Advanced Enterprise Services SSH

- Advanced IP Services

- Advanced IP Services SSH

- IP Services

- IP Services SSH

In all cases, you need IOS version 12.2(33)SRC.

As far as CPU load goes, you're right. There should be plenty of capacity on your router.