most networks use 192.168.1.device ip. what ip address is the network. That's where I would start.
there are 4 ip ranges that are NON-ROUTABLE (meaning they do not exist ON THE INTERNET [meaning they have not been SOLD to someone by a registrar])
one of my larger clients had their internal network setup as 194.44.22.xxx since the early 1980's
in 2006 we finally had to resubnet them when some ukranian companies started purchasing that range of ip's for their webites
THE PROBLEM THIS CAUSES is that your router gets all f**ked up when it queries an ip range and the reply is WHICH ONE, the external on, on the internet, or the one oon your internal network
this was only a problem for companies running unix or that sort of thing THAT PRE-DATED THE INTERNET
SO, you should stick to 192.168.SOMETHING for simplicity the other 3 non routables are often used by cable companies, who use the other ranges & TRUTHFULLY UNDERSTAND LESS ABOUT ACTUAL NETWORKING than a bystander who just happens to be walking by