Variable has incomplete type 'struct sockaddr_in'

Question

I try to use the

 struct sockaddr_in sin;

but if I use this I get

Variable has incomplete type 'struct sockaddr_in' 

and

Forward declaration of 'struct sockaddr_in'

as Error. I get error when I use Xcode4. In Xcode3.2 it works. Does someone know how to solve this error?? My imports are

#import <sys/socket.h>
#import <netinet/in.h>
#import <netinet6/in6.h>
#import <arpa/inet.h>
#import <ifaddrs.h>
#include <netdb.h>
#import <SystemConfiguration/SCNetworkReachability.h>

Answer 1

did you link your target with these two libraries?

• CFNetwork
• SystemConfiguration