Peter J. Holzer wrote:
On 2008-04-04 17:30:29 -0400, Robert A. Rosenberg wrote:
It also states that in the presence of an MX containing IPv6 address
references, an IPv4-Only stack should ignore the IPv6 addresses
Yes, of course. It cannot reach them anyway. Just as IPv6-only hosts can
ignore A records since they cannot reach them either.
I'm getting the impression Pete that some here don't realize that IPv6
is an entirely different TCP socket layer.
For folks who didn't know yet about IPv6, IPv6 is not just about given
the world an astronomical number of addresses allowing for every device
in the world to have its own IP address (and for PCs even 2 addresses),
we are talking about a new set of communication SOCKET methods.
IPv4 and IPv6 are very different and software NEEDS to change in order
to even BEGIN to thinking about supporting it.
Keep in mind that IPv4 allows for a 32 bit number or 4 bytes. IPv6 is
32 bytes! That means many software IP storage structures and records
will have to be altered from what is otherwise a natural word size
storage to one that is now NOT natural and will require extra
programming and engineering.
So if you are wondering why IPv6 is slow to be adopted, it is because
there are many unfeasible barriers to overcome for many still at this time.
For the majority of systems, it is not a plug and play solution.
Hector Santos, CTO