Adapting a legacy network to deal with growing pains is hard. Anyone who says different is probably lying, or hasn't administered a network outside of 'bedroom

Adapting a legacy network to deal with growing pains is hard. Anyone who says different is probably lying, or hasn't administered a network outside of 'bedroom scale' previously. Whilst everyone prefers to work with a blank canvas that is a rare opportunity, and one which still has constraints like budget limitations or "We need this by Wednesday!". All vendors have their foibles. No vendor is perfect. Datasheets are rarely 100% accurate, behaviour fluctuates based on what code train/version you're running on devices. Network vendors are like everyone else - humans - so just like everyone else they break things occasionally too. One of the best ways to mitigate this as demonstrated by some of the largest players is to have N+1 physical sites and to be able to control traffic distribution to each of them, including taking one entirely offline without your customers noticing that it's happened. It's also extremely hard to do when you start looking at how CAP theorem applies to your given application, and not just the infrastructure changes required to network it all together, but the application changes required to not have it just explode on you.