home 
wiki
wiki
Spelling: Broadcast
With reference to Ethernet [1], a broadcast is defined as a packet
that will be sent to all hosts in the broadcast domain (the area
between routers/switches).
A broadcast is addressed to a MAC [2] of FF:FF:FF:FF:FF:FF,
(equivalent to a subnet [3] mask of 255.255.255.255)
A broadcast domain is only able to be segregated by OSI layer 3
devices (routers). In effect, if a host is on the same network/subnet
[4] it will receive any broadcast sent on that network. However, the
boundary between layer 2 and 3 is blurred by VLAN Switches - which
also separate broadcast domains.
DIAGRAM 1: In this situation, server has sent a broadcast to the
network. Each workstation receives a copy.
Related to Broadcast, Multicast is simply a broadcast where the data
packet is not sent back to the source port. Where a hub broadcasts, a
switch multicasts. For example, OSPF Designated routers multicast link
state advertisements to all other OSPF routers in the area using the
multicast address of 224.0.0.5.
On the other hand, a unicast is simply transfer from one source to a
single destination.
-------------------------
It appears from my quick readings that we have:
* Ethernet broadcast * Limited broadcast * Directed broadcast
It may be worth expanding each of these into their own subsection,
especially as we are dealing with multiple subnets in our network.
This pdf [5] appears to be a reasonable overview.
I've made a couple of changes to your original, revert them if need
be.
Links:
------
[1] http://melbournewireless.org.au/?Ethernet
[2] http://melbournewireless.org.au/?MAC
[3] http://melbournewireless.org.au/?subnet
[4] http://melbournewireless.org.au/?subnet
[5]
http://waitaki.otago.ac.nz/telecom/tele402/lectures/lecture-15-ho.pdf
[EditText] [Spelling] [Current] [Raw] [Code] [Diff] [Subscribe] [VersionHistory] [Revert] [Delete] [RecentChanges]