[AccessD] OT: Public and private network

A church that I do pro bono for has an internet connection which currently is sent through a 
wireless router and shared in a simple workgroup lan.  They want to add a new lan segment which is 
"public", i.e. can be used by classes they give, to get to the internet, but they do not want those 
people to see or have access to the existing LAN / computers.

Am I correct that I can simply take two routers:

RouterA attached to the cable modem.
RouterA is the DHCP Server.
RouterA is the "Public" network and its wireless interface serves that part of the church.

RouterB connects its WAN to one of the LAN ports.
RouterB DHCP Server is turned off
RouterB is the private network and it's wireless interface serves that part of the church.

The cable modem location is several hundred feet from the church where the public network will be 
located.  I will use a Cantenna to beam the wireless down to the church.

http://www.cantenna.com/

I am considering using a bridge to pick up the signal from the Cantenna and retransmit the signal on 
another wifi channel.

My parts list

1 existing router (wrt54g IIRC)
2 new router (probably a wrt54g as well)
1 (or possibly 2) Cantenna

I am going to spend some time working with the system to see if I need a bridge at the far end or 
whether the cantenna will allow systems at the far end to see the internet directly through the 
cantenna.  I have no idea what the beam diameter will be a few hundred yards away, but I suspect 
that a wireless bridge and another wireless router at the far end will be required.

If anyone has done this kind of system and has words of wisdom please speak up.  I will be setting 
this up soon.


-- 
John W. Colby
www.ColbyConsulting.com