How to get the external ip in Objective-C

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?

Rhinoplasty

What sort of IP address are you expecting? The device is likely to be going through a WiFi or 3G network, etc. hence you're not likely to be able to retrieve any form of meaningful "external" IP address. – Buyse

Middaparka is right - from the device's viewpoint, 10.0.0.1 is its external IP address. – Myceto

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.

Exoergic

I like it. Not so much for prod apps but GREAT for debugging. +1 – Slavin

Unless you have like 10m DAU and call this every launch, then you really cost WhatIsMyIP.com A LOT of money in bandwidth for something that could be a local function. :o – Slapdash

Answer 2

Check Apple's PortMapper, does exactly what you want.

As of iOS7 this is irrelevant.

Leban

The PortMapper is for "Runtime requirements: Mac OS X 10.5" – Exoergic

I am using it for my iPhone app. – Leban

Nothing major that I remember. Works flawlessly, 3G or Wifi. – Leban

If you edit your answer with some additional information, I can remove my down vote from your answer. – Exoergic

There is absolutely nothing to add. PortMapper does the job flawlessly. End of story. Down vote if you like. – Leban

Give´s me null for the public ip Adress on iOS 7 – Therefrom

Same for me @chrizstone – Sleeve

Irrelevant for iOS 7+ – Leban

what do you mean by "As of iOS7 this is irrelevant."? – Phytography

That's the solution. @ssteinberg +1 – Kippy

It looks like PortMapper pings the DNS server for the IP address it sees... If the DNS server is internal to your network I believe PortMapper will give you the wrong IP. – Selfexpression

Answer 3

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

Feud

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

Brasilein