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New Member

Netflow Collector only see a few MB instead of GB of data

Customer is running a Collection Application called FLOW-TOOLS version 0.66 on a Unix System. Customer says that the CAT 6500 configs have not been changed at all. But all of a sudden the data collected by this FLOW_TOOLS application is only a few MBytes, whereas it should have been several GBytes.

SHOW TECHs of both CAT 6500 switches attached to see config, etc.

If this is the wrong forum - Network Management Forum - for this topic please point me to the right forum.

  • Network Management
5 REPLIES
Silver

Re: Netflow Collector only see a few MB instead of GB of data

This means that only the first pachets of the connection setup pas through the router. The rest is switched, and apparently the switch is not sending netflow data (anymore)

Or it was all proccess switches before and it is not longer.

Or the netflow data from the switch is not getting to the collector anymore

Check the devices, sup and msfc for config changes

Cheers,

Michel

New Member

Re: Netflow Collector only see a few MB instead of GB of data

From SHOW TECH is there something that is teling you that only the first packet of a flow is process switched and the others are process switched or is that just a guess for the reason for the problem.

Customer says no config change has been made on the two CAT 6500 or the collector Unix System / Collector Application.

Silver

Re: Netflow Collector only see a few MB instead of GB of data

It's a guess. The problems description fits.

The first show tech tells me that Catalyst is sending netflow info.

The question now is, is the MSFC card doing the same.

Cheers,

Michel

New Member

Re: Netflow Collector only see a few MB instead of GB of data

It is the correct behaviour for this configuration. Cat6500 uses MSFC only for the first packet, and the last packets are switched using PFC (CEF, dCEF). To correct configure Netflow export on the Cat6500, you must enable Netflow on the MSFC and on the PFC.

In ur configurations only the MSFC-netfow enabled, and the majority of traffic (PFC-switched) is missed!

For configuration guidelines see

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a0080160a2b.html

BR, Evgeny.

New Member

Re: Netflow Collector only see a few MB instead of GB of data

The problem was to do with MLS failing.

sh mls ip statistics

showed an IPC failure.

A reboot of both the routers has restored service.

No config change or additional config for PFC was required.

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