[ih] Memories of Flag Day?

[Andrew Sullivan]

Dear colleagues,

It seems to me that, quite apart from the historical experience, trying to require a flag day among the number of addresses that were the v4 Internet when everyone realized there was a problem was just a logistical impossibility?  Certainly, when I discuss the TCP cutover period with people (I am careful to note I was not involved), I like to point out that the rules at the time meant that you could still get a printed directory of all the _people_ connected to the ARPANET.  (I am aware that this directory was by then probably incomplete, but that it still made conceptual sense is nevertheless meaningful.)

Reminding people of that difference is quite important, because there are people today who are attempting to regulate the Internet as though they still have their arms around it as the DoD had just before the Internet emerged. I think it would be hugely valuable to remind people what the network population was in those days. 

I love this list. Thanks for all the contributions. 

A

— 
Andrew Sullivan 
Please excuse my clumbsy thums

> On Aug 6, 2023, at 17:41, Vint Cerf via Internet-history <internet-history at elists.isoc.org> wrote:
> 
> I think Andrew is correct in this analysis.
> v
> 
> 
>> On Sun, Aug 6, 2023 at 2:32 PM Andrew G. Malis via Internet-history <
>> internet-history at elists.isoc.org> wrote:
>> 
>> Brian,
>> 
>> There was a "slight" difference in scale between the two events - several
>> hundred ARPANET hosts vs. millions of IPv4 hosts.
>> 
>> But without the stick, at least some subset of ARPANET hosts would have
>> decided why bother, as long as we can continue to talk to each other? And
>> the ARPANET would definitely have continued as a dual-stack network, as
>> hosts that implemented TCP would also have an incentive to keep NCP going
>> (other NCP-only hosts). Remember, at that point there wasn't much other
>> incentive to implement TCP, as the rest of the Internet hadn't yet started
>> to appear.
>> 
>> Cheers,
>> Andy
>> 
>> 
>> On Sun, Aug 6, 2023 at 4:56 PM Brian E Carpenter <
>> brian.e.carpenter at gmail.com> wrote:
>> 
>>> Andy,
>>> 
>>> So, it was your fault that we decided that "no flag day" was a vital
>>> requirement for IPng :-). Seriously, I think that enough people
>>> remembered the 1983 flag day and definitely said "never again!"
>>> 
>>> Regards
>>>    Brian Carpenter
>>> 
>>> On 07-Aug-23 04:17, Andrew G. Malis via Internet-history wrote:
>>>> Miles,
>>>> 
>>>> I wrote the IMP code to enforce the flag day and ran the transition
>> from
>>>> the NOC.
>>>> 
>>>> To prepare for the flag day, we added a new bit to each port's
>>>> configuration in the IMPs. The bit said whether or not a port was
>> allowed
>>>> to use the NCP host-host protocol (port 0). If the bit was off, then
>> NCP
>>>> host-host packets were discarded by the IMPs.
>>>> 
>>>> There was a defined procedure in place well prior to the cutover for
>>>> approving exceptions to the no-NCP policy.
>>>> 
>>>> On January 1, I pulled the switch to flip the bits from "on" to "off"
>>>> except for the pre-approved list of exceptions.
>>>> 
>>>> A good number of hosts made the deadline, but additional exceptions
>> were
>>>> approved as the phone calls started coming in. The exception list
>>> continued
>>>> to grow in the first few days of 1983, but as hosts gradually got their
>>>> TCP/IP stacks working, their NCP permission was turned off.
>>>> 
>>>> As I recall, the exception list quickly shrank, and by the end of the
>>> year
>>>> there were very few NCP-only hosts left. There was certainly some
>> amount
>>>> of pain involved, but NCP would have hung around for much longer if the
>>>> switchover hadn't been enforced.
>>>> 
>>>> Cheers,
>>>> Andy
>>>> 
>>>> 
>>>> On Sun, Aug 6, 2023 at 7:35 AM Miles Fidelman via Internet-history <
>>>> internet-history at elists.isoc.org> wrote:
>>>> 
>>>>> Hi Folks,
>>>>> 
>>>>> Does anybody have some memories of the TCP/IP Flag Day they can share?
>>>>> 
>>>>> I'm doing some writing about "how network ecosystems develop" looking
>> at
>>>>> how the Internet evolved from the days the net was a gleam in a few
>>>>> people's eyes, Licklider distributed his famous memo, the NWG & IETF
>>>>> evolved, Flag Day, etc.  Also looking at the Environmental Movement
>>>>> (Earth Day, Whole Earth Catalog, ...), FOSS, Crisis Mapping,
>>>>> Entrepreneurship Support, Makers - all of which I've been up close and
>>>>> personal with, and now trying to document some common threads &
>>> techniques.
>>>>> 
>>>>> A particular focus is on organizing for significant
>>>>> changes/transformations - like the transition to IP that pretty much
>>>>> marks the birth of the Internet as we know it.  Hence a particular
>>>>> interest in what led up to the Flag Day, and how folks responded.
>>>>> 
>>>>> In particular, I'm wondering how folks organized at various network
>>>>> sites (universities, military bases, etc.) to respond to the mandate.
>>>>> Working groups, plans & programs, that sort of thing. How did folks
>> get
>>>>> their act together?
>>>>> 
>>>>> Anybody have any stories they can share?
>>>>> 
>>>>> Thanks Very Much,
>>>>> 
>>>>> Miles Fidelman
>>>>> 
>>>>> --
>>>>> In theory, there is no difference between theory and practice.
>>>>> In practice, there is.  .... Yogi Berra
>>>>> 
>>>>> Theory is when you know everything but nothing works.
>>>>> Practice is when everything works but no one knows why.
>>>>> In our lab, theory and practice are combined:
>>>>> nothing works and no one knows why.  ... unknown
>>>>> 
>>>>> --
>>>>> Internet-history mailing list
>>>>> Internet-history at elists.isoc.org
>>>>> https://elists.isoc.org/mailman/listinfo/internet-history
>>>>> 
>>> 
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> 
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