Nama: Gera genardya
NPM : 13112115
Kelas : 4ka02
Mata Kuliah : Sistem Terdistribusi
Exercise
3.10
Question : 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?
3.10
Answer
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
