efc bytes top

Specifies the number (based on traffic) of IP addresses obtained from the optional EFC module that will be probed as part of an active measurement group.

efc bytes top <number> [ starting-from <start> ]
 
efc bytes top percent <number>
 
no efc bytes top
 

• number--number of addresses (range: 1 through 1,000,000) or percentage (range: 1 through 100)
• start--exclude the top n addresses, where n is (start - 1), range is 1 through 1,000,000

Must be in active-measurement group configuration mode (config-engine-active), which requires privileged-level access.

Use once per active-measurement group.

1000

Use the efc bytes top command to use relative traffic volume as a limiting factor on the number of EFC-obtained IP addresses that will be probed as part of an active measurement group. Relative traffic volume is determined by the number of bytes that originated or terminated at the endpoint.

Without the percent keyword, the value of number means the number of the top (most-heavily trafficked) IP addresses collected by the EFC module that will be probed as part of the active measurement group.

If you include the percent keyword, CNA will probe the prefixes that account for the specified percentage of traffic.

The starting-from keyword is useful when you want to exclude a range of addresses already covered by another active-measurement group.

The following version of the command would result in the 10 busiest addresses in the data stream being probed:

efc bytes top 10
 

 

With the percent keyword, the command would result in the number of prefixes that account for the top specified percentage of traffic handled by the data stream being probed. The following example would result in probes being sent to the prefixes responsible for 90 percent of the traffic:

efc bytes top 90 percent
 

 

The total traffic value used for determining the top endpoints (whether number of prefixes or percentage of traffic) is based on traffic associated with endpoints already filtered for this active-measurement group.

The efc bytes top command is one of several commands which place restrictions on which endpoints obtained from the EFC module will be probed. See also:

• efc bytes minimum
• efc last-update-within
• efc exclude-prefix
• efc source

You can use them together in the same active measurement group.

Use the no form of the command to remove the top-traffic limitation.

For more information about EFC, see Chapter 2: Collecting Endpoint Addresses of the CNA Basic Monitoring Guide.