In my current role I speak to a lot of network engineers trying to automatically map their network topology. Actually it’s more than that, they don’t just want to discover devices, the want a port level diagram of exactly how all their switches, routers, servers, workstations, phones, firewalls . . . you get the point. Some engineers I speak to practically ask:
“Can this tool provide a detailed topology and physical map illustrating the rack number and space in the rack for all the devices in my environment without configuring SNMP?”
Seriously? Really?? While I may be dramatizing a bit, the reality is that network engineers regularly walk into hostile environments where the responsibility for the documentation and organization of equipment on the network has been sorely neglected. In some cases these engineers are filling a role that never existed before so nobody took these responsibilities seriously, and in others . . . let’s just say their predecessor may have left in less than amicable circumstances. In these situations engineers need tools that will flexibly discover and map the environment by any means necessary and provide them with the information they need to make sense of this strange new world they’ve thrown themselves into.
I feel for these engineers. I’ve been one of those professional services road warriors walking into a new environment every week and seen everything from well organized, well labeled, cable managed, SAS 70 certified datacenters where the greatest risk is getting stuck in the mantrap or having your coffee confiscated when you accidentally carry it onto the raised floor, to the cable spaghetti general purpose wiring closets where copper network cables are picking up EMF cross-talk from 240V electrical wiring that was dangerously close to a leaky roof. That’s no dramatization, and the point I’m trying to make is no matter how well funded, organized, or configured an environment may be, without a map to illustrate the physical and logical relationships between systems every engineer I’ve met would be lost.
Getting those maps early on and keeping them updated is a critical part of every network engineer’s role and a tool that will automate the process of discovering and drawing those maps is invaluable. That said we can’t expect miracles, tool developers are not the brothers Grimm, there are no networking fairies that will console into all your switches while you sleep and enable SNMP/CDP. There’s always going to be some amount of legwork to enable the environment to tell you what you need to know and it will be an iterative and ongoing process to keep that environment properly configured, documented, and mapped. The tools that minimize that legwork and maximize the value of our efforts as engineers is something truly worthy of legend.