The Blog

Guest Network set up with Linksys router and Airport Extreme

Posted on 25. Nov, 2009 by Philip in Apple, Hardware

The Dog Cafe in Footscray asked us to install a wireless network for their clients and a connection for their Macs so that guests were protected from sharing and the office network. Also they wished to file share amongst the office network Macs. Simple, the Apple Airport Extreme with guest network and a standard Linksys AG300 Modem router and TPG ADSL2+.

Well that proved to be an overstatement.

Whilst straight forward to understand in a network sense, not much information was available online or in the hardware documentation to sort out the relevant settings for both devices. Much of the information suggests forgetting the Airport Extreme as a DHCP device, bridging it and allowing the Modem to allocate IP addresses on the network. Whilst that is fine for most networks a guest network supplied by the Airport Extreme requires that it allocate IP addresses becoming the DHCP server for the two networks and isolating them from each other over WIFI. Simple, what about the Linksys modem? Bridge it and the PPPoE settings disappear and the Airport seems unable to to do this for the system, thus rendering the network operable but unable to connect to the internet.

The answer was stumbled upon after trying everything else that seemed logical.

Start with both devices in default settings, if necessary the paper clip in the reset hole with power on of course.

With an Ethernet cable plugged into the Linksys and the phone line connected, plug the Ethernet cable into a laptop or other computer that is not connected to a network. In Firefox (Safari seems to be unable to edit settings on the Linksys) type the default IP address for the modem into the URL field 192.168.1.1, hit return. Enter the default username password (admin/admin) and when the interface appears scroll down to PPPoE Settings and enter your ADSL username and password (supplied by your ISP). Scroll to the bottom and Save Settings. After the screen comes back you should get a connection to the internet. Test in another Tab.

Now on the default screen next to Internet connection type choose RFC 1483 Bridged

Now next to Network Address Server Settings (DHCP), select Disable for Local DHCP server. Beneath that set Auto Detect LAN DHCP Server to Enable. The IP address of the Router should not stay at 192.168.1.1. Choose something like 192.168.1.20 or other address not currently used by another device or within the 100 to 200 range.

Open Airport Utility (you will need software installer for the newer version of this device) and with WIFI turned on the Mac you should see the default screen with a new basestation to the left. Hit Continue to set up using the wizard.

Setup for network is fairly self explanatory from there although internet connection is through PPPoE using the username password provided by your ISP. Also it seems to make sense that you may wish to stick with 192.168.1 addressing for the network as the router has this as default. Either way it seems to work.

After all this messing around if the Airport restarts with a green light but you are still not connected try restarting the Modem and when the Airport goes green after that you should be fine.

Let me know how you go and also if you find any solutions similar, you may have a suggestion or perhaps I left out a step.