If you've grown up in a world where TCP/IP is the only network protocol then your understanding of the basic network interface configuration elements: IP address, subnet mask, default gateway might be purely functional. You know you need to configure these elements, but you might not understand why.

As the older generation of technologists age out of the profession, some of the technical history gets lost in the shuffle. The reasons behind why we do things is forgotten and we just do those things the way it's always been done. Don't mistake me for a cranky old man yelling at the cloud; this convenience is wonderful as we all get to stand upon the shoulders of giants and see a more distant horizon.

Let's climb back down from the giants' shoulders and look at what an IP address is and a bit about why subnet masks are necessary.

Have I ever told you the story about my introduction to disaster recovery?

Although IT platforms are notoriously complex and fragile, business leaders expect those IT platforms to run continuously without error or interruption, at all times, forever. There are many techniques for building an IT platform to be highly available, but I recommend against confusing high availability with disaster recovery. You will still need a plan to recover everything should disaster strike.