[ih] state of the internet probes? (was Re: AOL in perspective)

[Jeremy C. Reed]

On Wed, 17 Sep 2025, Greg Skinner wrote:

> There?s some discussion of routine pinging of gateways in several June 1983
> issues of the tcp-ip digest.  However, it concerned TOPS-20 and TENEX TCP
> implementations.  Anyway, the problem was serious enough that an entire
> issue of the digest (volume 2, issue 11) was dedicated to it.
> 
> https://github.com/matthewgream/www-securitydigest-org/blob/master/tcp-ip/a
> rchive/1983/06.txt.gz

Thank you. That is likely it. TOPS-20 and TENEX. Quick summary from 
scohn then:

   "TYMSHARE's TCP running on OFFICE-1 and OFFICE-2 had built into it a
   clumsy approach to maintaining a table on the status of internet
   gateways. ... both hosts were regularly "pinging", or exchanging
   single messages, with each of 23 gateways, at the interval of 37
   seconds. ...

   "... When the ping message is submitted the interface blocks until a
   message number is obtained. ... host would each be blocked 600 ms out
   of each 1.6 seconds or almost 40 % of the time. ..."