I recently got a Fonera+ to get free WiFi all over London in return for serving up some bandwidth in my neighborhood. Here's the problem. My modem is in the back of my flat, and I need to keep the Fonera off an Airport Extreme router at the front instead of between my ADSL modem and rear Airport Extreme. Here are the ports that Fon says must be adjusted in a firewall to allow the Fonera to work. If you install your La Fonera behind a Firewall that limits outgoing connections then it is necessary to make sure your La Fonera can access the following ports on the internet: Port Protocol Description 53 UDP/TCP FON DNS 80 TCP Fonera Website / Portal for payments etc. 123 UDP Fonera Clock synchronisation 443 TCP Portal for payments etc. 1645 UDP Radius authentication 1812 UDP Radius authentication 1813 UDP Radius authentication 1937 TCP Fon heartbeat and updates 1938 TCP Fon heartbeat and updates 3990 TCP Coofachilli port normally internal but may be needed depending on firewall/router My setup is ADSL Modem > Back Airport Extreme > AC Power Ethernet > Front Airport Extreme > Ethernet connected Fonera Do I have to adjust the firewall in both routers? Where and how in Airport Utility do I make these changes? It also seems that in any place I have found, it asks what services are needed. What services would this need? Please be very precise in your answers as I am sort of lost here. Here is the rest of the information from the page that contained the ports above To make sure you don't have to configure/install a Radius/Webserver locally, FON is offering free access to it's serverpark providing these services. You only have to allow your La Fonera to reach them through your firewall. You can't limit these services only to an ip-pool of *.FON.COM; hence FON has also backup servers elsewhere and allow eg access to Paypal, youtube, Google, Gmail, Flickr, ... La Fonera cannot be configured to use a WebProxy. We advise to "whitelist" your La Fonera on Mac/Fixed Ip adress so it can be used without the configuration of a Proxy. If you can not configure your Webproxy you will need to obtain a standalone internet connection without such security. We assume if such security is present then your ICT Policy won't allow a service like La Fonera to exist in your Network at all! If you became a Fonera without obeying your ICT Policy then give the La Fonera to someone who can install it without breaking Company law! http://wiki.fon.com/wiki/Firewall Thanks for any and all help.