Question : How to Setup Airport Extreme as DHCP Server on LAN with SonicWall

I am trying to setup an Airport Extreme on our LAN and utiize the Guest Networking feature, which required that DHCP/NAT be turned on on the Extreme.

Our network has a SonicWall SOHO3 firewall, which has been used as our DHCP Server.  I have turned DHCP off on the SonicWall, and turned it on on the Extreme.  The extreme is setup with a LAN IP address and the SonicWall as its Gateway.  The Sonicwall has both a LAN and WAN IP address.  NAT is turned on on both units.  The NAT Default Host of the Extreme points to the SonicWall's LAN IP.  

With this configuration, wireless clients through the Extreme work great.  But ethernet connected computers cannot obtain an IP.  If I manually input an IP, using the SonicWall as the gateway, I get internet access but cannot access the wireless computers connected to the extreme.  If I use the Extreme as the Gateway, I get no internet.

I have tried turning NAT off on the SonicWall, but I could not find a configuration that would get internet.

I have never tried anything like this before, so I really have no idea what I'm doing.  I would really appreciate the help!

Answer : How to Setup Airport Extreme as DHCP Server on LAN with SonicWall

Sure. There are many. In fact the sonicwall tz170 has this ability if you are acustomed to sonicwall (not my preference though).  

Almost any router/AP that supports multiple SSID will do this (Cisco 881w or Checkpoint Safe@Officecomes to mind). I am not familiar with the SonicWall Soho's full feature set but the fact that it is called soho leads me to believe that it won't work well with multiple SSID's. If your SonicWall supports VLANs and routing and firewalling between them then you should just be able to buy a multi SSID AP and build your own "Guest Mode".

The easiest way to do what you want is to put a switch in front of your sonicwall. Then buy a cheap wireless router just for your guests. Then they can share the internet connection and you don't have to worry about any fancy configuration.