[ih] ARPANET pioneer Jack Haverty says the internet was never finished

[touch at strayalpha.com]

Minor point...

> On Mar 4, 2022, at 7:43 AM, Guy Almes via Internet-history <internet-history at elists.isoc.org> wrote:
> 
> Miles,
>  The issue is not multicast vs not-multicast.
>  The issue is doing multicast at the IP / Layer-3 level vs doing multicast at the Application leve

Multicast needs to include L2 (see RFC3918, Sec 6). Without that, routers would need to do serial copy for every host inside each L2, which is prohibitive (i.e., this is why IGMP is *in addition* to PIM or other IP-level mechanisms).

Joe