I believe an advantage of using a passive monitoring technique is that it won't interfer with live traffic, as it does not inject traffic into the network or modify the traffic that is already on the network.
One drawback anyway, is that post-processing time can take a large amount of time with passive monitoring! A combination of the two monitoring methods seems to be the route to go.
Introduction: The "external-out enable" command is available for
configuration under the "router ospf process" in case of the IOS-XR
operating system. This command basically enables advertisement of
intra-area routes on the device as external routes in th...
Introduction Basic configuration for netflow Scale parameters for
netflow Netflow support Architecture Packet flow for netflow Inside the
LC CPU Netflow Cache size, maintenance and memory Sample usage Cache
Size Aging Permanent cache Characteristics Which...