Unfortunately, I've been in more than one hotel (or other location with open/public access to the network) where the implementers decided to just use either the

Unfortunately, I've been in more than one hotel (or other location with open/public access to the network) where the implementers decided to just use either the whole 10/8 network, a /16 (or more!) out of the 172.16/12 network, or the whole 192.168/16 network in one big, flat network. That can be a real PITA and annoys me to no end.