This can be done. There are commercial CISCO routers that will do 
this for you in one device. They are expensive. Most modern home 
routers will allow you to create a virtual wireless log in within a 
single router. I have a router that does this although I haven't 
employed the feature. You can also do this with two routers by 
assigning a separate IP number to the second router, and running the 
wireless from there while letting the firewall in the first router 
block access directly from the second router, however the second 
router will still be plugged into the LAN router which means it is 
not fully isolated. If something goes wrong your network could be exposed.

What I do is to use three routers. The first router which is a old 
wired 10/100 Linksys router is assigned an IP address of 192.168.3.1 
and your cable or DSL modum is plugged into it. I also plug my VOIP 
device into it because that does not need to work with any other PC 
or device. If everything else goes bad I can always plug directly 
into this router to access the Internet.

Then I have my personal network = LAN router plugged into the 
192.168.3.1 router as a client with a assigned IP address of 
192.168.1.1. This is a Gigabit network so the router and all the 
switches are Gigibit This 300N wireless is for my personal use and I 
assign it to channel 1.

Finally, my third router a TP-Link 10/100 with N150 wireless I run 
out to the middle of the house, for employees, friends, and family to 
use in both wired and wireless modes. It is  plugged into the 
192.168.3.1 Linksys as a client and I assign it  an IP address of 
192.168.2.1.I assign the wireless to channel 11 and give it a 
different SSID then my personal wireless .

The three router approach provides complete isolation of both the 
wired and wireless networks and also provides a lot of 
redundancy.  As long as the Internet modem and the 192.168.3.1 router 
is up and running then if one of the sub routers go down it won't 
effect the functionality of the others. Even if the Internet router 
goes down both LANs will still function.

Of course, every now and then I have to shut everything down and 
restart it all but it doesn't happen that often. I have been running 
this setup for at least four years. I have replaced routers, switches 
and other devices and it has remained very robust. After the initial 
shakedown, it has proven to be very reliable.

Mark Rode

At 10:15 AM 7/13/2012, you wrote:
>I want to isolate the wireless part from the local LAN. The wife 
>runs a business from home and has customers come here. Which she 
>want to be able to have customers or family members access internet 
>but not have access to the local LAN. I know this can be done with 
>two routers but can it be done with one router?
>
>Brad Feuerhelm

        The NOSPIN Group has added a new feature on our website,
           web based bulletinboard for questions and answers:
              Visit our sister website at http://nospin.com