Seeking IPv6/IPv4 Fundamentals

[clarkleach]

I have been scouring the interwebz for knowledge bases and tutorials regarding IPv6, IPv4, and transitional mechanisms. While I have found a number of resources that explain the theoretical aspects such as the address formats, I am missing some details necessary for to get a real grasp of this. Maybe I just haven't hit upon the magic search terms which will illuminate this subject for me.

The part that seems to be missing in all of my search results is the where and how of making the transistion from IPv6 to IPv4. It is my understanding that an IPv4 address can be encoded within an IPv6 address but thus far I have been unable to make much sense of this or make any of it work as I expect. I suspect my expectations may be contrary to what is actually happening.

Besides simply trying to wrap my head around this topic, I have an actual application which, if defined, may help to better explain my dilemma.

I am developing an IPv6/6LoWPAN-based distributed control network. I want nodes on this network to communicate with an application on a Windoze PC (for now) which is apparently IPv6 ignorant. What is required for successful UDP between the 6LoWPAN nodes and the application on the PC? Why does it seem to make a difference to the application whether the traffic is using IPv6 or IPv4? If a NIC has both an IPv6 address and an IPv4 address, why doesn't UDP traffic just automatically make it to the destination port regardless of IP address?

I will be grateful for any insight that will help me undertand what is going on and where.

[clarkleach]

So much for gurus... None here, I guess.

[2kaud]

So much for gurus... None here, I guess.

Yes, but this is a c/c++ network programming forum - and you are not asking a network programming question.

[VictorN]

...
I am developing an IPv6/6LoWPAN-based distributed control network. I want nodes on this network to communicate with an application on a Windoze PC (for now) which is apparently IPv6 ignorant. What is required for successful UDP between the 6LoWPAN nodes and the application on the PC? Why does it seem to make a difference to the application whether the traffic is using IPv6 or IPv4? If a NIC has both an IPv6 address and an IPv4 address, why doesn't UDP traffic just automatically make it to the destination port regardless of IP address?

I have no idea how the 6LoWPAN works... Sorry!
Some years back developing a server socket application I also had a "problem" for redistributing it (together with the client apps) to customers' computers that could work under XP and/or Vista and/or Windows 7. having or not having IPv6 installed...
So I just created two listening sockets on the server: one for IPv6 and another for IPv4...

I don't know would such an idea help you or not, but in my case it worked very good.