[e2e] What should e2e protocols know about lower layers?

[Joe Touch]

Perry E. Metzger wrote:

> Joe Touch <touch at ISI.EDU> writes:
> 
>>As Ran observed on the TSVWG mailing list, IPv6 lacks broadcast, one
>>could argue for reasons related to this. However, replacing the
>>well-known term broadcast with the magical 'anycast' doesn't replace
>>the need.
>>
> 
> Er,
> 
> 1) "Anycast" is something totally orthogonal, and the mere use of the
>    particle "cast" in the word does not make it related.


Granted; I was recalling a time when it was proposed that anycast might 
use broadcast; I see it now just routes all requests to a router, which 
means all broadcast-like discovery services are registration-based and 
centralized. Oh well...


> 2) Of course there is a direct equivalent to broadcast, which is
>    multicast. If you really do need to reach "everyone" you broadcast
>    to the all nodes multicast address. No protocols that I know of
>    actually need this in practice.


Except next hop discovery, i.e., the equivalent of ARP??

Joe