User`s guide

Introduction
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to an address. In the ATX implementation, the maximum number
of zones that a router may be configured is 22 ports. Each
configured zone may be available on any subset of ports.
How a Macintosh learns its address
A Macintosh learns its network address automatically; you don’t
have to assign addresses. This process is called address acquisition
and is performed every time a Macintosh enables its datalink,
either automatically at start-up or using the network control panel.
This process involves determining a network range from a router
(or using network 0 if no router is present) and then choosing a
host number on that range.
If the Macintosh had chosen a host number the last time it was
rebooted, it tries to use that number again. If it never had a number
assigned, it picks any unused number. To determine if a number is
available, the Macintosh sends out AARP probes. If a device
responds to the probe, a different number is tried until the
Macintosh finds an unassigned number.
Once the Macintosh has its address, it sends a request to a router to
determine if a previously used zone name is valid. The router may
either respond affirmatively or provide the Macintosh with a
default zone to use. The Macintosh may later change its zone
residence from the network control panel by asking the router for a
list of available zones. If no router is present, no zone name is
assigned.
How a router learns its address
Routers must also go through the address acquisition process, but
in a slightly different manner. The process begins each time a link
becomes active. The router first chooses an address in the start-up
network range (ff00-fffe) so that it has an address that other routers
may respond to before it learns its real network range. The ATX
probes to find its network range; it picks a network range and
sends out probes to see if it can use that range. Once the router