Another important topic to discuss is the impact of the network topology on your network monitoring
if an interface goes down, does it impact the ability of the NMS to collect data from your network
devices?
So as an example, if you viewed the network topology in something as simple as Visio or within one
of your management tools, how would an outage affect the ability of your network management system
to collect data from devices in your network?
If you had devices at a remote site and you wanted to collect statistics from those devices, how will
a link down affect your ability to get to those statistics?
If there was only a single link to the remote site and you had a central network management system and
the link went down, the NMS would no longer be able to access those devices to collect data.
So you may need to deploy a network management collector on the remote site to collect data remotely
rather than trying to collect everything from a central site.
So this would mean, as an example, that you deploy a distributed network management architecture rather
than having a single centralized network management system.
This is especially true where you have multiple data centers.
In that case, you might want to deploy multiple copies of NPM one in each data center that then forwards
data to an enterprise operation console or EOC.
So remember, if you can't get to it, you can't monitor it.
So it's important that you keep track of your network topology because you need to ensure that you have
reachability status when the topology changes.