When you deploy a network management system, it's typically going to add an overhead to your network.
This is especially true if you're using a query-based system that's polling the network using a very
short interval.
So you should determine the scope and impact on the network that the network management system will
have.
So, as mentioned, one of the things you need to think about is polling frequency, this means how
often you're going to poll devices to collect data.
The more often that you poll devices, the more granular and the more detailed your statistics are
going to be.
However, on the flip side, that means that it's going to have a larger impact on your network because
there's more traffic being transmitted on the network.
The network management system is polling the network on a more frequent basis, which puts more traffic
on the network.
And in addition, there's a higher load on your network devices because they have to reply back to the
network management station with information that you're trying to gather from that network device.
So more polling equates to more detail and quicker detection of issues, but it puts a higher load on
both the network and the devices in your network.
Now, once again, the advantage of more polling is that you have more detail and it's quicker to detect
issues.
However, on the flip side, it can create extra traffic on the network.
Now, most modern network management systems and a lot of modern network devices can handle a larger
amount of network management traffic than was possible in the past.
The processing power of your network devices and the speed of interfaces are a lot greater today than
they were a few years ago.
So it's not as much of a problem as it may have once been.
This is another reason that you want to leverage both event-based network management protocols, as
well as query-based network management protocols, event-based protocols once again offer real-time
unsolicited feedback from your network devices.
A router is going to inform the network management station
when an interface goes down with polling-based or query-based protocols, there's a query and response.
In other words, the NMS is querying a device for information, and it's responding or answering
back to that query.
Now, less polling equates to less bandwidth utilization, but in addition equates to smaller storage
requirements, which is another important thing to think about.
If you're collecting a large amount of data, you need to think about your disk requirements for your SQL
Server, which is where NPM stores data, large amounts of data equate to bigger SQL databases, which
in turn means that you need more disk space.