What does the IPv6 setting on my router do?

Question

I was just looking thru the settings of my Airport Extreme base station router and came across IPv6. There's a check in the box that says "Block Incoming IPv6 Connections". What exactly changes if I uncheck that box and allow the incoming connections? Are there certain internet applications that it would help or hinder? It says something about how IPv6 increases the address size or something?? Any networking pros please advise. Thanx!

Answer 1

The current Internet only uses IPv4.  So if your connecting to the Internet you would never see IPv6 traffic coming into your router.

The reason the setting is there is because the US Dept of Defense mandates that any equipment they buy be IPv6 capable.  So any vendor who has visions of being able to sell equipment to the Federal Government needs to support IPv6 to some capacity.

Answer 2

O.K. Here's the low down on IPv6

In the old days of IPv4 computers IP addresses were 32  bit characters (EX:192.168.2.1) That would be a Class C address. Each of those numbers can range from 0-255, although 0.0.0.0. and 255.255.255.255 are not valid as they are reserved for specialized network functions. As you can imagine this give MILLIONS of ip addresses. Add that to sub-netting and Super-netting and you literaly have billions of addresses.

However, there are not enough. I know, hard to believe, but it's true. The world is running out (already has run out) of IPv4 addresses. So in comes IPv6.

IPv6 supports 2128 (about 3.4×1038) addresses, or approximately 5×1028 (roughly 295) addresses for each of the roughly 6.5 billion (6.5×109) people alive today.[ In a different perspective, this is 252 addresses for every observable star in the known universe – more than ten billion billion billion times as many addresses as IPv4 supported.

Addresses in IPv6 are 128 bits long versus 32 bits in IPv4.

An example of an IPv6 address is:fe80::211:d800:97:c915%eth0.  As you can see, it is much more complicated than IPv4.

So what does this mean to you? Pretty much nothing. You can probably get away with turning it off without and problems. It will probably speed up your computer a bit, and it may make your connections to the net a little bit faster. However IPv6 is the future. Blocked or unblocked you probably won't notive the difference, but there really is no reason why you should bother. It won't hurt you to leave it on, and you MAY find some sites innaccessable without it, although I wouldn't bet on it.

Just ignore it. Treat it as one of the countless things that happen in the background of your computer and put it out of your mind. Hope this helped.