Different ip address on different devices?

2

When using google and various other websites like https://www.whatismyip.com/ I've noticed that my ipv6 is different for my phone, on my laptop, and on my desktop but my ipv4 address stays the same.

Why isn't my ipv6 the same across all devices but my ipv4 is?

I thought a ip address(s) is supposed to be shared across all devices using the same router to access the internet and then each device gets assigned a local ip address?

Side note: Most of the time websites show me my ipv6 address when asking what my ip address is (which is different depending which device I use)

I just set up a website and it works using the ipv4 address, but if for some reason I lose the ipv4 address, which ipv6 address should I use, the one that's hosting the server?

My isp is xfinity.

user987938

Posted 2019-01-21T15:22:10.510

Reputation: 23

5"I thought a ip address(s) is supposed to be shared across all devices using the same router to access the internet" — it was never supposed to be this way. It's only the way it is with IPv4 due to the shortage of IPv4 addresses. In an ideal world (i.e., with IPv6), this is not needed. As for your website, are you not using a domain to access it? – slhck – 2019-01-21T15:27:35.697

Not at this point no. So the router is assigning each device their own ipv6 addresses like they did back in the old days with ipv4? – user987938 – 2019-01-21T15:58:03.700

Yes. What that means for hosting depends on where you actually host your website. A device within your network? – slhck – 2019-01-21T16:05:11.180

Yes it'll be a device within my network – user987938 – 2019-01-22T02:41:44.037

Answers

5

IPv4 addresses are scarce. There are less than 4 billion addresses possible, while there are more people than that in the world. Therefore, your router allows multiple devices to share one IPv4 address. The downside is that the router need to keep track of who is talking with who. It will re-send all packets with translated addresses, which explains why all devices appear to have the IPv4 address of the router.

IPv6 is newer and designed to avoid this process altogether. Each device can have its own IPv6 address; you can easily get 4 billion IPv6 addresses just for yourself. The router may still keep track of connections, but it now only needs to do so for firewall reasons. There's no rewriting needed; packets that pass the firewall can be forwarded as-is.

MSalters

Posted 2019-01-21T15:22:10.510

Reputation: 7 587

Asked: 2019-01-21T15:22:10.510

Viewed: 208 times

Active: 2019-01-21T16:03:52.847