What are the disadvantages of using network-level broadcasting to locate resources:
i) in a single Ethernet?
ii) in an intranet?
To what extent is Ethernet multicast an improvement on broadcasting?

What will be an ideal response?

i. All broadcast messages in the Ethernet must be handled by the OS, or by a standard daemon process. The
overheads of examining the message, parsing it and deciding whether it need be acted upon are incurred by
every host on the network, whereas only a small number are likely locations for a given resource. Despite this,
note that the Internet ARP does rely on Ethernet braodcasting. The trick is that it doesn’t do it very often - just
once for each host to locate other hosts on the local net that it needs to communicate with.
ii. Broadcasting is hardly feasible in a large-scale network such as the Internet. It might just be possible
in an intranet, but ought to be avoided for the reasons given above.
Ethernet multicast addresses are matched in the Ethernet controller. Multicast message are passed up to
the OS only for addresses that match multicast groups the local host is subscribing to. If there are several such,
the address can be used to discriminate between several daemon processes to choose one to handle each
message.