"As sad as it is, documentation and Feature Navigator Tool are not the definitive resources."
Indeed, and for many years, I've only found the definitive answer being trying it on the actual platform with your desired IOS variant, and even that isn't 100% as sometimes features get into a release but this was unintended, and if the feature appears present, especially when not documented, if it doesn't work correctly, the "fix" might be pull it from the next release. Unfortunately, even if documented, and found not present or not working, the "fix" might be to add a release note, this feature isn't supported.
BTW, I don't want to sound particularity "negative" about Cisco, if fact, my experience with Cisco, compared to many other network vendors, their (documented) features usually work as described, and if not, they usually fix them.
Also with Cisco, compared to many other network vendors, their equipment is "feature" rich, and even with common "features", they might be doing much more "under the covers", then other network vendors do. (An example of the latter, Cisco's OSPFv2 implementation does things, not in the RFCs, and which don't the violated RFCs, but their OSPF works "better". [BTW "better" isn't just sales "cow chips", you might look into Cisco's OSPF exponential stability timers, hourly LSA pacing, iSPF, etc. Much, if you try to explain to management, boils down to, less likely to "crash" in operation.])
One of the "interesting" internal debates, was a large international enterprise I was working at, understood the above, and fought to only use Cisco network devices, but the question was, does this really matter for "vanilla" L2 switches, just doing "vanilla" L2 switching, when "vanilla" brand "X" switches cost so much less than Cisco switches?
