Ipswitch WhatsUp Gold User Guide - Ipswitch Documentation Server

Preparing network devices
In This Chapter
Determining which network devices to monitor .................................. 972
Manually configuring devices to export flow data to Flow Monitor973
Configuring sFlow enabled devices to export flow data to Flow Monitor 975
About Flexible NetFlow .................................................................................. 978
About Network Based Application Recognition (NBAR) .................... 982
About CBQoS ..................................................................................................... 984
Viewing potential Flow Monitor sources ................................................. 988
Using Flow Monitor to Configure Cisco NetFlow Devices ................. 988
Determining which network devices to monitor
When planning your Flow Monitor deployment, it is important to understand which network
devices are likely to provide you the information you want. In identifying those devices,
questions about the data flowing through an individual device, its location in respect to other
network devices and the types of addresses (internal/external) available to that device are all
of importance.
Are you interested in monitoring the internet gateway routers connecting to your ISP for
application level traffic analysis, performing forensics and diagnostics on a core router of a
public facing network, or monitoring your WAN core in order to plan for additional capacity?
The answers to these and similar questions about the purpose of your monitoring will
provide you with some indication as to which devices in your network are of most interest as
potential sources for Flow Monitor.
Once a potential Flow Monitor source has been identified, you should consider the location
of the device with respect to other networking devices, particularly those devices that
perform network address translation (NAT). Depending on where the source is located
relative to the device performing NAT, traffic to and from an internal (private) IP addresses are
reported differently in the exported NetFlow data.
If the device is inside the firewall, or if no firewall exists, the exported flow data
includes the internal IP address for devices generating and receiving traffic. This
allows you to pinpoint the exact device in the internal network to which the traffic
belongs.
972