switching cache, rewritten, and sent to the chosen exit interface. Other packets
associated with the same session then follow the same path. All processing is
carried out on the interface processor, including the CRC. Optimum switching is
faster than both fast switching and Netflow switching, unless you have imple-
mented several access-lists.
packets while troubleshooting a network problem.
required processing is done right on the VIP processor, which maintains a
copy of the router's routing cache. With this arrangement, even the first
packet doesn't need to be sent to the route processor to initialize the
switching path, as it does with the other switching algorithms. Router effi-
ciency increases as more VIP cards are added.
application-utilization information. Because of all the additional data that
Netflow collects (and may export), expect an increase in router overhead--
possibly as much as a five-percent increase in CPU utilization.
support Netflow switching, and the Cisco 3600, 7200 and 7500 series rout-
ers provide its implementation.
mation. All of this is stored in the Netflow switching cache, according to the
individual flow that's defined by the packet information (destination
address, source address, protocol, source and destination port, and the
incoming interface). The data can be sent to a network management station
to be stored and processed there.