How long much advanced notice do ISPs need to deploy IPv6?

How much notice is adequate when changing widely used behavior on the
Internet?

When the ARPANET changed from NCP to TCP/IP how many days advance notice
was needed?

When the Internet changed from IPv4 to IPv6 how many days advance notice
was needed?

When the COM and NET zone behvior was changed to eliminate NXDOMAIN how
many days advance notice was needed?

How much notice is adequate when changing widely used behavior on the
Internet?

Widely deployed Filters, including uRPF, would probably qualify as this
right?

When the ARPANET changed from NCP to TCP/IP how many days advance notice
was needed?

When the Internet changed from IPv4 to IPv6 how many days advance notice
was needed?

I'm going to show some (alot?) ignorance here... BUT: won't the network
go: pure-v4 -> v4+v6 -> v6 (probably with v4 tunnels) -> pure-v6

I don't think its just going to go: POOF! one night, nor in one year...
Judging by how long it takes people to upgrade a simple major application
or OS it'll take YEARS to upgrade entirely to pure-v6.

of course, I could be completely wrong.

Sean Donelan wrote:

How much notice is adequate when changing widely used behavior on the
Internet?

When the ARPANET changed from NCP to TCP/IP how many days advance notice
was needed?

Umm, hard to remember that long ago, and haven't looked at IENs in ages,
but should memory serve me correctly, the first TCP/IP documents I read
were circa 1978, and the cutover was circa 1983.

However, I wasn't directly involved -- my email eventually went through
a gateway at UMich to ARPAnet -- and the network I was cobbling together
on a NOAA+EPA grant used bisync, X.25 (for the satellite links), and an
assortment of serial protocols (such as 5-bit baudo coded weather data)
that we mixed together on Alpha somethingorothers and Interdata 7/32s,
first with the proprietary OS, and then with a new-fangled thingy called
"Unix". (Now, we'll drag out the old stories for the kiddies.)

The folks at Merit fed me the TCP/IP documents, and were a lot more
closely involved in the cutover.

When the Internet changed from IPv4 to IPv6 how many days advance notice
was needed?

Well, we finished the initial design in 1993 (I was part of the original
design team), and the cutover will be (heavy sigh) probably never....

After all, it's time to design the next generation!

When the COM and NET zone behvior was changed to eliminate NXDOMAIN how
many days advance notice was needed?

<sarcasm> Oh, there was advance notice? </sarcasm>

I wrote my first DNS implementation in 1987. I know it's still in use
on a number of old routers and dialup access boxen. My guess would be
another 16 years, or so, to clean up the entire mess.

Easier to eliminate the problem at the source!

I was a system/network admin at the University of Texas at Austin when
the old ARPNET NCP was phased out in favor of IPV4. There was not a
single cutover date, but rather both protocols were run side by side for
a few years as I recall. This allowed plenty of time for testing, etc.
Of course, the installed system base was much smaller in those days. UT
had 3 machines directly connected to the local ARPANET IMP and
no campus area network. In 1983 the 128.83.0.0/16 assigned to
UT was just being deployed. So the cutover to IPV4 was relatively
easy.

A major change in the operational protocols today would have a much
greater impact and require a much longer deployment and testing cycle.