Re: Unusual use of IP Broadcast Address

[Steve Deering <[e-mail]>]

> I don't think I fully comprehend the situation, but it seems to me
> that if you want to send to a host whose address you don't know
> but which is known to be on subnet 129.83.14, you should use the
> directed broadcast address 129.83.14.255.  Using 255.255.255.255
> does not seem correct.

Bob,

Wendy said that her PCs don't necessarily know that they are on subnet
129.83.14, so they wouldn't be able to recognize 129.83.14.255 as a
broadcast address they should accept.

Upon re-reading her message, I realize that I may also have misunderstood
what she was proposing when I wrote my response.  The references to a
modified version of routed seem to imply that the "broadcast" packets will
be originated from machines other than the Sun that has the serial links to
the PCs.  If that's true, what she is proposing is significantly at odds
with the IP architecture (treating an all-ones broadcast as a directed
broadcast to a remote subnet known as a special case by the routers).  IP
multicast would satisfy her requirement without bending the architecture.

Steve