How to get correct IPv6 Ip address?

Question

I am trying to display the ip address of connected networks in android. I am using the following code. But it returns 2 IPv6 ip address. How to find the correct ip address from that?

I am using the following code:

List<LinkAddress> linkAddresses = connectivityManager.getLinkProperties(connectivityManager.getActiveNetwork()).getLinkAddresses();
        for (LinkAddress linkAddress : linkAddresses) {
            Log.i("","LinkAddress getAddress "+linkAddress.getAddress() + "");
            Log.i("","Is IPV6 " + (linkAddress.getAddress() instanceof Inet6Address) +"");
            Log.i("","Is IPV4 " + (linkAddress.getAddress() instanceof Inet4Address) +"");
            Log.i("","Is isLinkLocalAddress " + (linkAddress.getAddress().isLinkLocalAddress()) +"");
            Log.i("","Is not isLoopbackAddress " + (!linkAddress.getAddress().isLoopbackAddress()) +"");
        }

Now I am getting 4 ip addresses.

LinkAddress getAddress /fe80::2d0:caff:fe00:5ad6
LinkAddress getAddress /2401:4900:2305:14e:2d0:caff:fe00:5ad6
LinkAddress getAddress /2401:4900:2305:14e:28e2:5192:e38f:3e9
LinkAddress getAddress /192.168.43.176

I can identify fe80 is Link Local Ip address and 192. is IPv4 address. But I am confused to identify IPV6 address from this. Please help me to find out the IPv6 ip address.

There are three IPv6 addresses there, not two. All three are correct. Which one to use depends on what you are doing. — Michael Hampton

Sander Steffann Sander Steffann · Accepted Answer · 2018-12-18T12:27:00

Both IPv6 addresses are valid. It's normal to have multiple addresses per interface. Both are in the same subnet (2401:4900:2305:14e::/64). When you look at the interface ID (the second half of the address) you'll see that one has ..ff:fe.. in the middle. That's a sign that that address is probably derived from the MAC address of the interface. The other address is a temporary address that will change over time to protect the privacy of the user.

But in short: both addresses are completely valid and usable.

How to get correct IPv6 Ip address?

1 Answers