https://github.com/tonymillion/Reachability
//Initialize
[TLIReachabilityController sharedController];
//NSNotification example
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityDidChange:) name:kReachabilityChangedNotification object:nil];
- (void)reachabilityDidChange:(NSNotification *)notification {
Reachability *reachability = (Reachability *)[notification object];
if ([reachability isReachable]) {
NSLog("Reachable");
} else {
NSLog(@"Not reachable");
}
}