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NetFlow collects the Packet source, Port number, Destination Packet size, and Protocol number. Understanding what ports are commonly used on your network can help you in determining if abnormal activity is coming through. Using the Conversation Summary feature in opFlow allows for a detailed look into all conversations happening on your network. There may be a lot of conversations happening across your network, in Figure 1 below, you can see that the ports are filtered to only show Src Port 443 allowing you to see specific and relevant traffic easier. These packets can be sorted in ways that help you view and understand the information more clearly. In this example, packets received are sorted in descending order to see if the packet count is unusually higher than normal; this is why understanding what normal packet sizes are as well as the ports/sources commonly used on your network is important for any network engineer.
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