I'm not sure how to describe my network requirement.

I've looked at Guest WLAN, Dumb and Routed AP, Bridged AP, Bridged Client, etc.  So far don't see what I'm interested in.

I have a small collection of Raspberry Pis, some wired, some wireless, and some wifi based sensor and actuator boards all working together for a home automation system.

I already have a pfSense based firewall (192.168.0.1) for my home, but I'd like to set up a subnet connected to the WAN port of my WD MyNET 750 running OpenWRT.  It would isolate all of the home automation system (LAN/Wifi) on this subnet (e.g., 10.0.5.1).

It would be good to be able to access the internet out and in when it is connected to the home LAN, but it should be able to run independently as a stand-alone system.  IOW, if I want to, I can disconnect from the WAN connection and my system (not requiring internet access to run) would still work; but if I wanted to download an online package, I could plug in the WAN connection and download as needed.  This OPenWRT setup would ideally support DHCP/DNS only for the devices connected to this subnet.

What might be the name of this "recipe"?

I've been accepted to have a booth at this year's maker fair (http://makerfaire.com/bay-area/) so the stand-alone requirement would help with my hoped-for setup to show my home automation system running live.

Would appreciate any tips, tricks, and/or tutorial references.

Thanks,
Chris

1. Purchase a router supported by OpenWrt

2. Install OpenWrt (branch or trunk)

3. Change network.lan.ipaddr to 10.0.5.1

1. I have a WD MyNET 750
2. it's running latest OpenWRT
3....  seems extremely simple

If I change the LAN IP address to my desired 10.0.5.1...

does that get me all the way to having a subnet of 10.0.5.1 which can deliver DNS/DHCP to that subnet (host1.mysubnet.xyz) which can stand alone for either wired LAN ports or wifi connected devices, AND if WAN is connected to my home network gets those subnet devices connected to the internet?

I've looked around and it seems there are so many options that I feel overwhelmed and feel like I could be breaking it before I've even got it started.

Thanks for your advice,
Chris.

Yes, the default configuration for OpenWrt, plus changing the LAN IP address, is exactly what you are describing.

Wow!  OK. I will give it  try when I get home tonight.

Thanks.