Network visibility

Mel Beckman mel at
Thu Oct 21 15:55:20 UTC 2021

On Oct 21, 2021, at 8:19 AM, Owen DeLong <owen at<mailto:owen at>> wrote:

No, but you are ignoring the point of my message…

The TCP/IP internet existed _BEFORE_ the flag day you mentioned. The flag day was the end of NCP, not the beginning of TCP/IP. IIRC, at the time,


But we’re not talking about the birth of TCP/IP. We’re talking about the birth of the capital-I Internet, which by definition runs exclusively on TCP/IP, and that didn’t start until Jan 1, 1983. Although there was experimentation using IP during 1982, that was still ARPANET. It was the guaranteed exclusive availability of IP that made 1983 the Internet’s birth date.

And no, it’s not analogous to the eventual IPv6 transition, because both IPv5 and IPv4 are Capital-I Internet standard protocols.


it was IP version 2, but IP versions 2, 3, and 4 came in relatively rapid succession of each other and 4 was the first version with (relatively) clean
layer separation between 2, 3, and 4.

According to , TCP/IP was developed starting in 1975 and
declared the official future standard of the ARPANET in March, 1982, with a transition plan supporting both protocols (NCP and TCP/IP)
until January 1, 1983.

January 1, 1983 is more analogous to the future happy day we finally turn off IPv4 at the majority of peering points and PNIs than it is to the
past days when IPv6 began being deployed.

True, the initial deployment of TCP/IP and the flag day were much closer together for the implementation of IPv4 and deprecation of NCP
than has been the case for IPv6 deployment and IPv4 deprecation, but nonetheless, it is still true that there were at least several months
of TCP/IP deployment, testing, and use at multiple sites and on multiple systems prior to the deprecation of NCP on January 1, 1983.
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