Compatible Systems 5.4 - Manual (Page 291)

Appendices 285
AppleTalk Routing Example
Each AppleTalk physical network segment is assigned a network
number/range by the routers on the segment. The network number (or range
of numbers) can be between 1 and 65,279. In the diagram above, 100-200 is
the network range for the backbone, and 1001 is the network number for the
local net segment.
Non-extended and Extended AppleTalk Networks
The original AppleTalk specification, which is now referred to as AppleTalk
Phase 1, used only a network number, not a network range. A network
number was a sixteen bit value, which allowed numbers between 1 and
65,534 to be used. The address of an individual device on the segment
consisted of the network number, along with an 8 bit node address value. This
scheme meant there could be a maximum of 254 devices per network
segment. While this was more than adequate for LocalTalk networks, it was
a major constraint on Ethernet networks.
AppleTalk Phase 2 introduced the concept of extended networks. While the
node address remained an 8 bit number, network segments could now be
identified by a range of network numbers between 1 and 65,279. Each
number in the range allows 253 node addresses. These Phase 2 extended
ranges should be used for all new AppleTalk installations.
“Seeding” a Network Segment
Establishing the network number/range for an AppleTalk network segment is
referred to as “seeding” the network. You should generally only have one
Backbone Local Net
Router
Workstation
Workstation
Net: 100-200
Net: 1001