3Com 2500 manual Named Entities, Routing In An Appletalk Environment

7-2 CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT

AppleTalk® A network in an AppleTalk internet is a cable segment attached to a router. Networks Each network is identified by a network number or range of network

numbers. The network administrator assigns these numbers from a range of valid network numbers.

Two AppleTalk network numbering systems are currently in use: nonextended (Phase 1) and extended (Phase 2). 3Com routers support extended network numbers. While the LANplex system will not translate Phase 1 packets to Phase 2 packets, it will route packets to a Phase 1 network. The LANplex system anticipates that a gateway exists between the two networks to translate the packets.

An extended network can span a range of logical networks. Network numbers in an extended network consist of a range, such as 15 through 20. This numbering scheme allows for as many as 16,580,608 nodes, although the actual cables will not support this many nodes.

AppleTalk® Nodes A node in a AppleTalk network is any addressable device, including workstations, printers, and routers. Nodes are physically attached to a network. Each AppleTalk node is identified by a unique AppleTalk address that each node selects at initialization. The address consists of the node’s network number and a unique node number.

Named Entities

When a device on the network provides a service for other users, the network administrator can give the device a name. The name appears on the Chooser menu of the Macintosh with an associated icon. For example, the Chooser of the Macintosh can include a printer icon. When you select the printer icon, several printer names can appear in a list, such as Laser1, or Laser 2. The Name Binding Protocol (NBP), described later in this chapter, translates these device names into AppleTalk addresses.