Merge pull request #1554 from nicolas-fort/warning_netflow

Netflow: add warning message

Author: c-po

docs/configuration/system/flow-accounting.rst

@@ -42,6 +42,10 @@ exported.
 Configuration
 =============
 
+.. warning:: Using NetFlow on routers with high traffic levels may lead to
+   high CPU usage and may affect the router's performance. In such cases,
+   consider using sFlow instead.
+
 In order for flow accounting information to be collected and displayed for an
 interface, the interface must be configured for flow accounting.