There's also 172.16/12 :) But yeah I agree. If you're running a VPN for a large company it's kinda hard to avoid such conflicts.
In my work we use 10.0.0.0/8 but of course some people use the same at home even though 192.168/16 is way more common. In general I find 172.16/12 the least common in the field.
I personally use a range towards the end of the 172.16/12 reservation for my home network for exactly this reason. Ever since I made the change five years ago I’ve never suffered any conflicts when running a VPN in or out.
I know the old Apple extreme and time machine routers used to default to 10 rather than 192 ever since then I’ve kept my internal routing within that block.
It just looks nicer to me which shows the power of Apple and how easily I am influenced.
I like the 172.12/16 to company network, especially small companies with limited support resources. Getting employees on VPN is much simpler as virtually no home routers use that range.
A trick is to use something in the 10 range but not /8 - 10.185.203/24 will work on a 10/8 network (assuming no actual host overlap) as it’s more specific and will route first.
In my work we use 10.0.0.0/8 but of course some people use the same at home even though 192.168/16 is way more common. In general I find 172.16/12 the least common in the field.