Overview

NBAR provides two levels of application recognition: coarse-grain and fine-grain modes. Coarse-grain mode optimizes performance. Fine-grain mode provides NBAR's full application recognition capabilities, but with a higher performance cost.

By default, NBAR operates in coarse-grain mode. NBAR automatically changes to fine-grain mode when required, based on the configuration and traffic patterns. Typically, it is not necessary to change NBAR's automatic behavior, but you can configure fine-grain mode manually, using the procedure described below.

Forcing fine-grain mode for specific applications may be useful for monitoring a subset of applications, without adversely affecting performance, while other applications continue in coarse-grain mode.

How to Configure Fine-Grain NBAR for Specific Applications

To override NBAR’s automatic behavior and force fine-grain mode, use the following procedure. The procedure enables specifying applications individually by name or specifying applications that match a specific attribute value, such as "business-relevance = business-relevant".

Configure fine-grain mode:

enable
configure terminal
ip nbar classification granularity fine-grain { [protocol protocol-name] | [attribute attribute-type attribute-value] }
exit

Display the currently configured NBAR classification mode:

show ip nbar classification granularity { [protocol protocol-name] | [attribute attribute-type attribute-value] }

Example

Device#enable
Device#configuration terminal
Device(config)#ip nbar classification granularity fine-grain protocol cisco-media-audio
Device(config)#exit
Device#show ip nbar classification granularity protocol cisco-media-audio

Protocol                  Force mode
------------------------------------- 
cisco-media-audio         fine-grain