Greetings, for a little bit of background the network we are dealing with is moving into it's 3rd generation of administration. That being said there are still devices/configuration's that are left over from the 1st. Documentation is slim but improving. The roadblock we are faced with is: from the viewpoint of upper management the network works, why change it? It's hard to communicate how even though something is working it can work better. I feel as though the overall health of our network is degrading and at some point we will reach a critical mass and it will all come tumbling down. So can anyone share any suggestions / personal experiences / advice to overcome this roadblock in management thinking? What are some key concepts / areas to look at when assessing a network?
"I feel as though the overall health of our network is degrading..."
Why do you feel that way? Use the answer to this question to direct monitoring efforts. If you can show time series data that allows one to extrapolate towards network degradation, you're well on your way to justification.
Basically, evidence is key. Especially when you're making a push to get resources applied to a new project.
Also, continue to improve the documentation. While doing so, identify the weak points of the network architecture. If you can identify single points of failure, that should also help build a case for bolstering the network infrastructure.
Lastly, make sure to correlate the information you collect with the potential impact to productivity (i.e. if the network goes down, is the business dead in the water?).
I would start out with a schematic of your current setup, explain in easy terms how the current setup works. Then highlight problems with it. Some topics might be:
In other words, make clear why you have a bad feeling. After that, explain what you would like to change and how this solves the problems you explained earlier, and why it is a good business decision to do that.
While I usually don't have to explain why and what I want to change, I'll do all of the above nevertheless, mostly just for myself. This helps me sorting out if something is really necessary or if I am a victim of my never ending desire to try out new things.
Are you referring to strictly the networking components or to all systems as a whole?
Are you seeing an increasing trend of higher utilization and\or congestion, decreasing performance, increasing incidents that lead to downtime, etc., etc?
In addition to all the sensible answers about how to justify replacing the network, you could try to sell the network infrastructure as an enabler, not just an overhead... what changes would the business like to make to the way it works? You could propose upgrading the network and adding PoE and QoS, so that you can support IPT and Video... or propose using QoS to make sure that things that interactive application performance takes priority over backups and email.