Most customers are using sampled netflow/sFlow not un-sampled, so we also need to support it. The reason customer is using sampled netflow/sFlow is huge traffic volume of routers/switches. The router/switch will be overloaded if there is no sampling to netflow/sFlow generation, so almost customers are using sampled netflow/sFlow in live network.
Though there is no exact guideline about sampling ratio of netflow/sFlow, enterprise customer is using 1,024 sampling ratio and ISP/IDC customers are using over than 4,096 sampling ratio.
Unfortunately, I can’t find any sampling option for netflow/sFlow configuration. The version that I’m using is 6.2.2. In my humble opinion, we need to add sampling ratio option to netflow/sFlow configuration.
Let me know if you need anything.