_internetReachability = [IKTReachability reachabilityForInternetConnection];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:IKTReachabilityChangedNotification object:nil];
[_internetReachability startNotifier];

- (void)reachabilityChanged:(NSNotification *)note{
IKTReachability* curReach = [note object];
NSParameterAssert([curReach isKindOfClass:[IKTReachability class]]);

NSLog(@"state:%@",[curReach currentReachabilityStatusString]);
/*
* Do something
*/
}