Hi,
such a beast already exists, there is a protocol for
NNTP over multicast. The sending news relay propagates
all new articles over multicast IP. All listening relays
collect articles from this multicast stream (but since it is
UDP they might miss some of them). After that they still open
a plain TCP NNTP session to update those articles which
had not been transferred properly in the multicast stream.
I suggested earlier to also replace NNTP with a new mail protocol.
If we implement something like this, then connecting to news servers
and subscribing to newsgroups might be turned into subscribing to
multicast groups. Should be taken into consideration.
regards
Hadmut