Technical data

E-2 AppleTalk Routing 90362-01
Network Numbers and Ranges
With AppleTalk, large networks (called internetworks) are subdivided into
smaller networks by network numbers. All AppleTalk routers use
AppleTalk network numbers to differentiate their ports. These network
numbers work similarly to ZIP codes by helping the NetBlazer identify
which network connection a packet needs to be routed to.
Generally, when you are setting up a network you will pick one number for
the network, as opposed to a range of numbers. However, if you have more
than 64 AppleTalk nodes on an Ethernet network, you should use a range of
network numbers. The numbers from 1 to 65,279 are legal numbers. (Apple
has reserved the range from 65,280 to 65,534.)
If you are setting up a very large network, pick a range of one number for
about every 64 nodes. For example, if you have 256 nodes, pick four net-
work numbers such as 1000 to 1003. Because of AppleTalk’s dynamic
addressing, you always want to have more node addresses available on a
network than you have devices. The ratio of 1:64 assumes you have many
more workstations than servers. If your ratio of servers to workstations is
about even, however, you don’t need to use as large of a range.
Zones
To help users find network services, Apple devised a way to associate
names with networks. These names are called zones. AppleTalk zone names
are stored in the router along with the network numbers.
Unlike AppleTalk network numbers which have to be unique, AppleTalk
zone names can be duplicated throughout the network. Zone names are
typically selected on the basis of physical location or function. A small site
may have a single zone name such as Chicago Office . A larger site may have
several logical zones; for example, Accounting , Engineering , Marketing ,
and Customer Support .
For the NetBlazer, you need to be aware that a LocalTalk LAN connection
can only have one zone name (and one range number), but other LAN
connections (such as Ethernet) can have multiple zone names associated
with them. For information on setting zones, see “Configuring AppleTalk
Routing” on page 4-8.