Broadcast Addresses; Multicast Addresses - Novell NETWARE 6-DOCUMENTATION Manual

Broadcast Addresses

Multicast Addresses

34
NetWare TCP/IP Administration Guide
Then, you assign host addresses on each subnet as follows:
...
Using this method leaves a buffer zone between the subnet and host addresses,
which enables future network growth.
The method of assigning subnet addresses described in this section
summarizes the method suggested in RFC 1219, On the Assignment of
Subnetwork Numbers. For a complete description of this method, refer to RFC
1219.
There are four types of broadcast addresses: directed broadcasts, subnet
directed broadcasts, all-subnets directed broadcasts, and limited broadcasts. A
directed broadcast has a destination IP address with the network portion of the
IP address set to Class A, B, or C network, and the host field set to all ones.
Directed broadcasts are sent to all hosts on the specified network.
If the network is divided into subnets, each subnet has a subnet directed
broadcast. A subnet directed broadcast has an IP address with the network
field set to the network identifier, the subnet field set to the subnet identifier,
and the host field set to all ones.
An IP address with both the subnet and host field set to all ones is interpreted
as a broadcast directed to all the subnets on the network. That is, the first router
on the specified network broadcasts the IP address to one of its subnets. If
broadcast forwarding is enabled, the receiving routers in that network forward
the broadcast to other subnets.
An IP address with all bits set to 1, that is 255.255.255.255, is called a limited
address. It is directed to all hosts on the subnet from which the broadcast
originated.
A multicast address is used to send packets to a group of hosts or routers. A
packet with a multicast address is received by all hosts and routers belonging
to that multicast group. Class D addresses are reserved for multicast addresses.
They range from 224.0.0.1 to 239.255.255.255.
Novell's TCP/IP implementation uses five multicast addresses. Two are used
by OSPF to multicast packets to OSPF routers. These addresses are 224.0.0.5