OT: IPv6 Questions

Hey guys,

I am just learning up on IPv6 and have a couple of questions. An example
would probably be best to convey what I am trying to get my head around.

Let's say I want to run IPv6 globally over the Internet. I am assigned an
global unicast IPV6 address block and start advertising this block to my
ISP's with BGP.

What happens when an IPv4 host out on the internet wants to access my
companies web service? Would I need to run dual stack and have a
corresponding global IPv4 block advertised as well?

Another example. Let's say a host is running dual stack somewhere out on the
Internet and decides to use IPv6 by default. Is there a way that these hosts
can "Fail back" to IPv4 if for example some destination out on the Internet
is IPv4 only? i.e. IPv6 DNS lookup does not return an IPv6 address therefore
do an IPv4 DNS lookup?

You can start to see why the take up of IPv6 has been so slow. Why run dual
routing tables when 99% of the Internet are running IPv4?? What is the
driving force? Sure Addresses are running out but unless the RIR's start
stripping me of my IPv4 addresses why do I care?

Thanks for any clarification guys as usual.

-Aaron

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Received on Wed Feb 16 2011 - 16:02:06 ART