I think this should be a fairly simple one to answer for you guys hopefully. I have a couple years experience of fairly basic AD management and I've come into a small/med size company where the IT manager was running the show on his own for years and has suddenly left so I'm going through the AD infrastructure to get to know the setup and see where improvements can be made.
We have 3 physical sites (main office, small satellite office and DR site), and there are 3 subnets displayed under Sites in AD sites and services representing each. The only thing is that in our main office we have 8 vlans in total, but only the 'server vlan' which hosts the DC's on this site is configured in AD S&S.
My question is, should I add the other 7 vlans we have into the AD S&S subnets? Everything seems to work without them being there, I just can't remember if it's best practice to add all the other non-DC subnets into there as well? And if that is the case, what's the reason for doing so?