Force iOS device app to talk through the local WIFI network

Question

I'm building an application that will run in a museum with a local area wifi network without internet access, for some strange reason I'm not able to fully "join" this network with an iOS device. Enabling internet access on this network solves the problem...

The network should provide only a web server and a DNS server, the access point has a DHCP server, android devices can connect to the network without problems.

When I try to join the network with the device it remains in a "spinning wheel" status, the DHCP server log on the debian server says it has assigned an address to the iOS device, and if I check for the wifi address with an application (like iSys o SBSettings) I see the WIFI DHCP assigned address.

But when my app (or safari) tries to connect to the web server the request is routed through the 3G connection and not completed.

In my app I'm using the standard "Reachability" framework from Apple to check the reachability of a provided host name through the wifi connection and I get 0 on the SCNetworkReachabilityFlags mask....

I'm quite sure the problem is due to the fact iOS (5.1 in my case) tries to check the reachability for some "standard" host in the network, before routing traffic through the WIFI connection.

Anyone knows what an iOS device do to "validate" a WIFI network? I can add hostnames or simple dummy services to the server machine if this can help me connect the device to a LOCAL-only network :)

Answer 1

It seems that iOS doesn't like to join networks without a gateway, also if the network is local you have to setup a correct gateway address.

Setting the gateway as the server itself did the trick and the device started to route TCP/IP over my local area wifi network.