How to get the external ip in Objective-C - iphone

Question

I looked for some code that will help me to get the ip that the iPhone connect with.
I find this one:
- (NSString *)getIPAddress
{
NSString *address = #"error";
struct ifaddrs *interfaces = NULL;
struct ifaddrs *temp_addr = NULL;
int success = 0;
// retrieve the current interfaces - returns 0 on success
success = getifaddrs(&interfaces);
if (success == 0)
{
// Loop through linked list of interfaces
temp_addr = interfaces;
while(temp_addr != NULL)
{
if(temp_addr->ifa_addr->sa_family == AF_INET)
{
// Check if interface is en0 which is the wifi connection on the iPhone
if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:#"en0"])
{
// Get NSString from C String
address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
}
}
temp_addr = temp_addr->ifa_next;
}
}
// Free memory
freeifaddrs(interfaces);
return address;
}
but the problem is that he get me this ip
10.0.0.1
How to get the external ip?

Answer 1

The easiest way to get your internet ip address from code is to use NSURLConnection.
For the URL you can use:
http://www.whatismyip.com/m/mobile.asp
or
http://checkip.dyndns.com/
Just parse the return data and you have your external ip address.

Answer 2

Have a look at the example in my second Answer here.
In a nutshell it uses *http://www.dyndns.org/cgi-bin/check_ip.cg*i to get the extenal I.P

Answer 3

Check Apple's PortMapper, does exactly what you want.
As of iOS7 this is irrelevant.

Answer 4

Late to the party, but https://api4.ipify.org or http://api4.ipify.org returns nothing else but the external IPv4 address of your connection. Code:
NSURL *ipifyUrl = [NSURL URLWithString:#"https://api4.ipify.org/"];
NSString *externalAddr = [NSString stringWithContentsOfURL:ipifyUrl encoding:NSUTF8StringEncoding error:nil];
https://api6.ipify.org returns the external IPv6 address and https://api64.ipify.org either the IPv4 or the IPv6 address. Simple documentation can be found at https://www.ipify.org