I have seen a lot of the "flavor of the month" network management ideas go the way of the dodo, but there is one that has withstood the test of time, the Network Operations Center. The NOC is a collection of tools, process and people with a clear set of common goals. Here's the first of three blogs addressing my take on the Network Operations Center (NOC) goals and priorities.
It's as simple as this, you cannot manage what you cannot see. This may seem too basic to be a main goal for a NOC, but that depends on how you define visibility. If you set up a network management software to ping all the devices on your network, you could say you have 100% visibility. The problem here is that the visibility is in breadth only; there is no depth to this type of network monitoring. The only information I get using ping is that here is an interface responding to an echo request. To add depth you could enable SNMP on the devices and poll them from your network management system. Now you can see a lot about the devices and how they are interacting with the network. There are thousands of SNMP objects to tell you how well a device is performing and how the device is configured.
Although you now have a great microscope for inspecting devices in detail, you lack visibility into how the network is delivering data. You can see where interfaces are saturated using SNMP, but you cannot see what is causing the saturation. That is where NetFlow comes in.
NetFlow examines the IP headers and tells you who and what are using the interface. This is great information, but you can look even deeper into the network. The piece of the visibility puzzle that is still missing is Quality of Service (QoS) visibility. How is the excess traffic impacting the network performance? For this, you would add a synthetic traffic modeling tool, such as Cisco's IP SLA.
IP SLA sends specific types of test traffic from a source device to a target device. The source device stores the results of the test in a MIB for network management system retrieval using SNMP. Now you have network management visibility breadth and depth, and hopefully some really big NOC displays to show it off!