QoS | Cisco IP Protocol Discovery

In a few day ago, I ever post about IP accounting feature can get IP accounting information in interface Cisco router. Now I will show, how to get protocol based on application or mention NBAR (network based application recognation). This feature is one of way to classification classes to define (QoS) Quality of Service. Other classification classes in QoS are IP DSCP, IP ACL etc. To define QoS based on MQC (modular QoS CLI) need to 3 step are classification classes, policy define and apply policy to interface.

This topic just explain how to use simple classification classes based on protocol discovery or NBAR. To use NBAR just need default setting, it feature can automatic classification packet cross the interface based on application with specific port. If Cisco router known type of application, name of application or type shown in result NBAR, but if not just port number and type of packet.

To enable NBAR in interface use, from interface configuration

(config-if) #ip nbar protocol-discovery

To simple show result of NBAR

#sh ip nbar protocol-discovery

To show resulf in Top N

#sh ip nbar protocol-discovery top-n N

To other feature in resulf of NBAR use ?

#sh ip nbar protocol-discovery ?                     
  interface  Show for a specific interface
  protocol   Show stats about a particular protocol
  stats      Show Stats
  top-n      Show Top-N protocols by bytes
  |          Output modifiers