How to tell if IPv6 is actually being used on my Win7 machine? 1

[jsteph]

Hi all,
When I look in network properties under my ethernet adaptor, I see both v4 and v6 properties listed, and each has an address when I do ipconfig.

So the question is multipart:
How would I know which address is being used when, say, I open a browser?

Does it just pick one protocol randomly and go with it?

Does it just use v4 because it knows v6 does not have much saturation yet?

Does it change based on the site visited, and if so, does it do some sort of 'handshaking' to decide what to use on each and every request?

I recall asking a similar question many years ago, when Tcp/Ip was in it's infancy and it had to be installed as a separate program. I'd ask how windows (3.11 and maybe win95 at the time) chose whether to use tcp/ip or whatever the 'standard' was at that time--I think it might've been Netbui or netbios or something along those lines.

Anyway, nobody could answer that. So now i'm wondering the same--what protocol is my computer actually, physically using each time it uses tcpip for anything, whether browsing, vpn, emailing, whatever.
Thanks for any info,
--Jim

 

[IPKONFIG]

They are both being used. Hook up a protocol anaylzer to your network and you'll see that when you fire up an application that each stack will attempt to communicate using its protocols. The differece, is that you'll only get responses back from the v4 instead of the v6. Most of North America uses v4 while Asia uses v6 and your ISP's do what's called 6-to-4 tunnels so that you can communicate with v6 nodes using v4 addresses. We'll all be v6 one day, but were not there yet. Hope this helps.

"I can picture a world without war. A world without hate. A world without fear. And I can picture us attacking that world, because they'd never expect it."
- Jack Handey, Deep Thoughts

 

[jsteph]

ipkonfig,
Thanks, that helps. So is it fair to say the ball is in the ISP's court as far as whether to let IPv6 traffic through?

For example, if I were to communicate with an Asian website, I'm sending v6 requests, and I assume it's responding in v6...so it's just the ISP's router that is makeing the decision?

Would it help performance and/or security if the isp were to, say, recognize that a request was made using v6, and if the isp's router was smart enough to recognize that v6 traffic also responded, then it could let the v6 traffic come back to me?

I haven't tried this, but what would happen if I turned v4 off? Would I get nothing because the converts all v6 responses, or would I see just the sporadic v6 sites?
Thanks,
--Jim

 

[IPKONFIG]

In the situation that you describe, your v6 requests don't make it off your LAN, because more than likely your gateway is not configured to support it. Your v4 requests however do make it out the gateway and when they reach that ISP in Asia, it goes through that 6-to-4 tunnel (in reverse) and then gets to that website for example. Conversion is done at the ISP. If you turned off v4, you'd be dead in the water. You should however, turn off v6 if your gateway doesn't support it as you'd have less traffic in your LAN.


"I can picture a world without war. A world without hate. A world without fear. And I can picture us attacking that world, because they'd never expect it."
- Jack Handey, Deep Thoughts

 

[jsteph]

ipkonfig,
Thanks very much!
I think that gives me a good lay of the land,
--Jim