Cisco 4507R FLOWSLOSTERR

[manjesh.michael]

Hi,

WS-C4507R Switch (Supervisor V-10GE / IOS - cat4000-i9k91s-mz.122-25.EWA12.bin) is generating the below logs - %C4K_HWNETFLOWMAN-4-FLOWSLOSTERR: Netflow stats lost either due to hardware hash collisions or full hardware flow table. Stats lost for 128159929 packets. - The below mentioned actions have been carried out, but still the issue persists.

- Netflow has been disabled from global config mode and enabled on the required interfaces
- Flow aggregation and flow/cache timeouts have been enabled
- Not seeing any bug which can generate these log messages
- Show platform hardware netflow statistics utilization output shows - Total Used 8192 (100.0% - Bucket Count)  
                        131017 ( 99.9% - Used Entry Count)

Please let me know the root cause behind this log message. Is there any way to suppress the generation of this log?

Best Regards,

Mike

[glen.grant]

sounds like the netflow table is overflowing .  Sounds like you need to adjust how often it is throwing out idle flows .  Adjust the timers so that they are shorter.  Don't know of a way  to keep them out of the logs..

[regodin]

ip flow-cache timeout active 1	Breaks up long-lived flows into 1-minute fragments. You can choose any number of minutes between 1 and 60. If you leave it at the default of 30 minutes your traffic reports will have spikes. It is important to set this value to 1 minute in order to generate alerts and view troubleshooting data.
ip flow-cache timeout inactive 15	Ensures that flows that have finished are periodically exported. The default value is 15 seconds. You can choose any number of seconds between 10 and 600. However, if you choose a value greater than 250 seconds, NetFlow Analyzer may report traffic levels that are too low.

Check these values.

Rick