How to get the public IP address of the device

Question

I found this sample code to get all local IP addresses, but I don\'t find an easy solution to get the public IP.

A legacy class from Apple allowed to do that ... bu

Answer 1

I find both Andrei and Tarek's answers helpful. Both are relying a web URL to query the "public IP" of the iOS/OS X device.

However, there is an issue with this approach in some part of the world where URL such as "http://www.dyndns.org/cgi-bin/check_ip.cgi" is censored as in andrei's answer:

NSString *theIpHtml = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://www.dyndns.org/cgi-bin/check_ip.cgi"]
encoding:NSUTF8StringEncoding
                                                  error:&error];

In this case, we will need to use an "uncensored" URL within the region such as http://1212.ip138.com/ic.asp

Note that the web URL could use a different HTML and encoding than what Andrei's answer could parse - in the URL above, some very gentle changes can fix it by using kCFStringEncodingGB_18030_2000 for http://1212.ip138.com/ic.asp

NSURL* externalIPCheckURL = [NSURL URLWithString: @"http://1212.ip138.com/ic.asp"];
encoding:NSUTF8StringEncoding error:nil];

NSStringEncoding encoding = CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);

NSString *theIpHtml = [NSString stringWithContentsOfURL: externalIPCheckURL
                                                   encoding: encoding
                                                      error: &error];