This blog may need prior reading of my first blog about Flexible NetFlow. We have already discussed about the advantages of Flexible NetFlow and migration from traditional NetFlow versions to FNF. To make this transition smooth Cisco provides the option of pre-defined flow records which can be used to configure Flexible NetFlow without investing a lot of time. And as I mentioned earlier it also helps your existing NetFlow V9 collector to parse exported data. However to use Flexible NetFlow to its fullest potential or to monitor a specific network behavior, you should create your own customized records. 

        Let’s see how to configure Flexible NetFlow to export flow statistics. Flexible NetFlow export can be configured in three easy steps.

1. Configure the exporter

2. Configure the Flow Monitor with the pre-defined Flow Record and Flow Exporter attached to the monitor.

3. Add the Flow Monitor to the interface to monitor either ingress (input) or egress (output traffic).

1. Configuring Exporter

                    Flow exporter can be configured with a unique name. Multiple Flow exporter profiles can be configured. Below is the configuration to configure Flow Exporter.

flow exporter <exporter name>

destination <ip address of ME NFA>

transport udp <port number>

Example configuration:

flow exporter me_nfa_analyzer

destination 192.168.1.1

transport udp 9996   

2. Flow Monitor and Flow record configuration

Flow record configuration defines the fields exported via NetFlow protocol. Flexible pre-defined flow records are based on the original NetFlow ingress or egress caches. Cisco provides a unique keyword to identify the pre-defined records and these records can associated with a Flexible NetFlow Flow record configuration. The Flexible NetFlow "netflow-original" and netflow ipv4 original-input are predefined records and these two records can be used interchangeably to export the basic key fields and time stamp fields. Flow monitors can also include packet sampling information if sampling is required.

flow monitor <monitor name>

record netflow-original

exporter <exporter name>

cache timeout active <seconds>

cache timeout inactive <seconds>

Example Configuration:

flow monitor me_nfa_monitor

record netflow-original

exporter me_nfa_analyzer

cache timeout active 60

3. Adding Flow Monitor to the interface

Flow Monitor has to be attached to a specific physical or logical interface to export flow statistics for that particular interface. Below is the configuration to attach flow monitor to a specific interface.

interface <interface name>

ip flow monitor <monitor_name> input

Example Configuration:

interface serial0/0

ip flow monitor me_nfa_monitor input

   And the above configuration can be verified by "show flow monitor" command. As I mentioned earlier Flexible NetFlow has numerous advantages and has the power of supporting new performance monitoring statistics as soon as they are available.  Flexible NetFlow is an evolving technology available in Cisco devices to help with visibility into how network assets are being used and the network behavior. 

Please find more information on FNF here.

   ManageEngine constantly studies the market and user demands to support new technologies. In fact ManageEngine NetFlow Analyzer is the first tool to support multiple bandwidth and performance monitoring technologies like NetFlow, NBAR and CBQoS in the market. And currently ManageEngine NetFlow Analyzer supports Flexible NetFlow without any issues. Please write your questions to netflowanalyzer-support@manageengine.com. We are happy to assist you at any moment.

Thanks

Raj 

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Released!

NetFlow Analyzer Enterprise Edition 7.0 is packed with a load of amazing features. The official PR is available here.

And happy to announce that NetFlow Analyzer Enterprise Edition supports Cisco NetFlow (and other flows), Cisco NBAR and Cisco CBQoS out–of–the–box. Download the 30-day free trial and try it out in your network setup.

Following are some of the new features added in 7.0.

• Validating QoS policies with Cisco CBQoS - Enterprise edition now supports Cisco CBQoS and provides report on the per-class pre policy, post policy drops and queues. This new feature complements the already existing support for Cisco's Network based application recognition (NBAR), helping in application mapping and providing better quality of service. Read more...
  


• User based dashboard page for guests / Operators - Each user can have their own dashboard, only viewing devices that need to be monitored by them, which can be sorted based on utilization, speed etc.


• Business hour alerts - makes sure that the users do not have to worry about the alerts that might be generated during non-business hours. With the new version of NetFlow Analyzer, business hours can be preset as per the enterprise's need and the alerts can be activated only during that period.


• Exclude IP address(es) option in IP groups - During creations of IP groups, the exclude option makes it much easier to exclude only particular addresses from a network as the requirement may be.


• Radius authentication - Radius Server is useful in centralised management of user credential details. Once the user roles are defined in the User Management feature of NetFlow Analyzer, subsequent authentication of the user profiles can be done from the Radius Server.


• Exclude encrypted applications - Enabling NetFlow on cryptomap tunnel interfaces double counts the ESP / GRE traffic. That can be prevented by applying this filter on cryptomap tunnel interfaces.


• Output interface suppression - WAN optimizers compress the packets and therefore the flow size varies. The size of the packet going in and coming out is not the same, and the readings can be misleading and confusing, to say the least. To avoid this, "Output Interface Suppression" can be used. The interface in which the compression takes place (destination/output interface) can be suppressed.


• ACL related drops - Access control filter drops the flow information which contains data pertaining to dropped traffic due to Access Control List.