[ML-General] linux networking questions

[david]

Seems like lately I've forgotten everything I've ever known. <sigh>

I need to be able to access subnets at home; everything is behind a 
firewall to the Internet.

My PC's are all dhcp in the 192.168.1.x address space.

I'd like to be able to talk to other addresses from these PC's.

Specifically:
192.168.7.2 -- Beaglebone Black default IP Address works just fine.

but

192.168.10.1 -- particular RPi 2 address from downloaded image does 
not.  Of course, that Pi is a wireless one, while if I turn off the 
wireless and connect a house cable, it gets assigned 192.168.1.56 (for 
example) and that works fine.  BUT, the wifi address is still not 
accessible unless I make the wifi laptop get on the RPi 2 as it's dhcp 
server and then the laptop gets assigned 192.168.10.x. <sigh>  (Same for 
the Android tablet.)  How do I get everything to play nice with each other?

Bought a NAS server and set it's address to 192.168.200.1 -- and 
*nothing* in the house could see it until I changed it's address to a 
192.168.1.x.

Help, please.

Thanks,
David Merchant