We are seeing a limitation with netflow on 7ks risky to do 1:1 flows and TAC Cisco sees enabling 1 out of 1 sampling rate as a risk and they say it is not recommended (CPU spike etc) on 7ks and its not recommended , we have been testing it on several L3 interfaces and its working ok so far but were a bit unsure whether to try all interfaces as per Cisco's advice its not supported , has anybody tried to do all there l3 interfaces was any strange behaviour seen ?
Is there any other recommendation anyone else got or has ?
Problem Description
The netflow is enabled on N7K, but the reported traffic rate by netflow is different from the real traffic rate on interfaces.
Action Taken
- Checked the netflow configuration and hardware installed.
- Shared the netflow configuration guide and explained that M3 only supports sampled netflow.
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus7000/sw/system-management/guide/b_Cisco_Nexus_7000_Series_NX-OS_System_Management_Configuration_Guide/b_Cisco_Nexus_7000_Series_NX-OS_System_Management_Configuration_Guide_chapter_011000....
Resolution
As we discussed, The M3 supports only sampled netflow due to hardware limitation, so, the tranditional/1:1 netflow isn’t supported.
----
F2, F2e, F3, and M3 Series modules support only sampled NetFlow.
Thanks Mark
