Chapter 17 - Planning Your AppleTalk Network

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Before you set up Services for Macintosh (SFM) on a computer running Windows NT Server, it's a good idea to create a plan for your network. In such a network—one that includes both PCs and Macintoshes—a major consideration is how to plan the physical setup of the network, including the network media. (Network media are different types of local area networks, each of which uses different cabling, topology, and network cards. Examples are ethernet, token ring, LocalTalk, and FDDI.) If your network has multiple media types, you must find a way to make them work together.

Note The basic concepts of AppleTalk networking are important to master. Because few of these concepts are involved in PC networking, they might be unfamiliar. For more information about AppleTalk networks, see "AppleTalk Networks" and "Planning your AppleTalk Internet," later in this chapter. Also refer to the Windows NT Server Concepts and Planning Guide for information on planning a network.

Planning the Physical Setup

As you plan how to physically connect your PCs and Macintoshes, the first thing to consider is network media. Each network media type has its own method of cabling and network topology, and each requires different network hardware.

Windows NT Server supports four types of media:

  • Ethernet 

  • Token ring 

  • LocalTalk 

  • FDDI 

Ethernet and token ring are common network media in PC networking. LocalTalk is used in AppleTalk networking. FDDI, although not as common, is based on token ring and is designed to be used with fiber-optic cabling. Every Macintosh includes hardware and software that enables it to be a client on a LocalTalk network.


Media Speeds 

To set up a computer running Windows NT Server to communicate with both PCs and Macintoshes, you might need to install two (or more) network cards in the server: one card (such as ethernet) for communication with the PCs and another card (such as LocalTalk) for communication with Macintoshes. If the Macintoshes are also using ethernet (or EtherTalk®) cards, you'll need only one network card.

The following section describes how to connect your network.


Suppose your server and PC clients use ethernet, and your Macintoshes aren't currently attached to any network. (They have only their built-in LocalTalk hardware and software.) To enable the computers running Windows NT Server and the Macintoshes to communicate, choose one of these methods:

  • Install a LocalTalk network adapter card on the server in addition to the ethernet card already installed. 

  • Install ethernet cards on each Macintosh. 

  • Install an ethernet/LocalTalk router. 

Solution 1: Install a LocalTalk Card on the Computer Running Windows NT Server

You can install a LocalTalk network adapter card on the computer running Windows NT Server, in addition to an ethernet card. You can then set up the Macintoshes on a LocalTalk network attached to the server's new LocalTalk card. The server will communicate with the PC clients by means of ethernet and will communicate with the Macintoshes by means of LocalTalk.

This solution is fairly inexpensive because it requires that you buy only one additional network adapter card. However, LocalTalk is not as fast as ethernet; consequently, network performance is not as good as it would be if all the clients used ethernet. Because you can have a limited number of Macintoshes on a LocalTalk network, this solution might be impractical if your network has a large number of Macintoshes.

Solution 2: Install Ethernet Cards on the Macintoshes

You can install ethernet network adapter cards on all the Macintoshes and attach them to your existing ethernet network. The server will use its existing ethernet card to communicate with both PC and Macintosh clients, which can all be attached to a single physical ethernet network. The following illustration shows a network using this solution:


Solution 3: Install an Ethernet/LocalTalk Router

You can install an ethernet/LocalTalk router, which translates data on the network between the two media. (These routers are made by several companies.) Windows NT Server running SFM can also act as a router between ethernet and LocalTalk. Windows NT Server, however, must have both an ethernet and LocalTalk card installed in it. (See the Note at the end of this section for more information on using the computer running Windows NT Server as a router.)

By using an ethernet/LocalTalk router, the server can still use its ethernet card, and you can put the Macintosh clients on a LocalTalk network and attach the router to both the ethernet and LocalTalk networks. All data transferred between the server and the Macintoshes passes through the router. To the server, all the Macintoshes appear to be on the ethernet network. The following illustration shows a network that uses an ethernet/LocalTalk router.


To use this ethernet/LocalTalk router, you must be able to bind the AppleTalk protocol on the server to an ethernet card on the server.

This is a low cost and useful solution if you want to make printers on the ethernet available to Macintosh clients. However, performance is degraded by using a router. A network with LocalTalk clients is not as fast as an all-ethernet network.

Note Because a computer running Windows NT Server can function as a router, it can also function as an ethernet/LocalTalk router—as long as it has both an ethernet network adapter card and a LocalTalk card. To connect one physical network of Macintoshes to several servers, you can install a LocalTalk card on one server, and that server can function as a router, enabling the Macintoshes to reach the other servers on the ethernet network.

Advanced Examples

Depending on which clients you have, the issues you face when deciding how to connect them can be more complex than those discussed previously. For example:

  • Windows NT Server uses ethernet, but some of your Macintoshes use ethernet and others use LocalTalk. 

    Solution: You can install a LocalTalk card on the computer running Windows NT Server to communicate with the Macintoshes that use LocalTalk, or you can install ethernet cards on all the Macintoshes, or you can use an ethernet/LocalTalk router. 

  • Windows NT Server uses ethernet, but some of your Macintoshes use ethernet and others use LocalTalk. You also have some Macintoshes that have token-ring network cards. 

    Solution: Install a token-ring network card on the computer running Windows NT Server to communicate with these Macintoshes, in addition to whatever solution you choose in the previous example for the Macintoshes that use ethernet and LocalTalk. 

These examples can be used to install FDDI rings as well.

AppleTalk Networks

Because AppleTalk networks differ from PC networks, you must consider some special concepts and issues when you set up an AppleTalk network.

The first concept you need to understand is the internet. (Note that this is a different concept than the Transport Control Protocol/Internet Protocol [TCP/IP] Internet.) Most large AppleTalk networks are not single physical networks in which all computers are attached to the same network cabling system. Instead, they are internets, which are multiple smaller physical networks connected by routers. Routers maintain a map of the physical networks on the internet and forward data received from one physical network to other physical networks. Routers are necessary so that computers on different physical networks can communicate with one another. They also reduce network traffic on the internet by isolating the physical networks. In other words, routers only send data that is usable by a network.

Some routers on the network are seed routers. A seed router initializes and broadcasts routing information about one or more physical networks. This information tells routers where to send each packet of data. Each physical network must have one or more seed routers that broadcast the routing information for that network.

Not all routers must be seed routers. Routers that are not seed routers maintain a map of the physical networks on the internet and forward data to the correct physical network. Seed routers perform these functions too, but they also initialize the routing information, such as network numbers and zone lists, for one or more physical networks. (See "Determining Seed Router Placement on a Network" later in this chapter.)

A computer running Windows NT Server with SFM can function as a seed router or as a nonseed router. If it is a seed router, it must be the first server you start so that it can initialize the other routers and nodes with network information. If it is a nonseed router, it cannot be started until a seed router has initialized all ports. You can also use dedicated hardware routers (such as those made by Cayman Systems®, Shiva®, Solana, Hayes®, and others) on your network.


Phase 2 AppleTalk Networks

There are two types of AppleTalk networks: Phase 1 and Phase 2. You must use Phase 2 to run Windows NT Server and SFM (For more information, see Chapter 15, "Introduction to Services for Macintosh.")

Phase 2 includes these features:

Supported media types Token ring, LocalTalk, ethernet, FDDI. Network numbers LocalTalk networks have a single network number; EtherTalk and TokenTalk® networks can be assigned a network range, allowing for more nodes on the network. AppleTalk zones Each LocalTalk network must be in a single zone; each EtherTalk and TokenTalk network can have multiple zones, and individual nodes on a network can be configured to be in any one of the network's associated zones. Number of nodes per network A node is any type of device on the network. Each client, printer, server, and router is a node on an AppleTalk network. LocalTalk networks can have as many as 254 nodes (but are actually limited to 32 or fewer nodes because of media capacity); EtherTalk and TokenTalk networks can have as many as 253 nodes for every number in the network range, for a maximum of 16.5 million nodes. (But don't specify this many nodes; network media cannot physically accommodate this large number of nodes.)

Note In this book, the terms ethernet and token ring are used in descriptions of network media. For discussions on the implementation of an AppleTalk network on ethernet or token ring, the respective Apple product names—EtherTalk and TokenTalk—are used. For more information, refer to an AppleTalk manual.

Routing Information

Routing information includes

  • A network number or network range associated with each physical network 

  • The zone name or zone list associated with each physical network 

  • The default zone for the network (if the network has multiple zones) 

The network number or network range is the address or range of addresses assigned to the network. A network number is unique and identifies a particular AppleTalk physical network. By keeping track of network numbers and network ranges, routers can send incoming data to the correct physical network. A network number can be any number from 1 through 65,279.

LocalTalk networks can have only a single network number; EtherTalk, TokenTalk and FDDI networks can have network ranges.

A zone is a logical grouping that simplifies browsing the network for resources, such as servers and printers. It is similar to a domain in Windows NT Server networking, as far as browsing is concerned. In LocalTalk networks, each physical network can be associated with only one zone. However, for EtherTalk, TokenTalk, or FDDI, you have more flexibility in assigning zones. Each EtherTalk, TokenTalk, or FDDI network can have one or more zones associated with it, and each zone can include servers and printers on one or more physical networks. This allows you to group servers and printers logically into zones so that users can easily locate and access the servers and printers, no matter what physical networks they are on.

Each Macintosh client on the network is assigned to a single zone. However, each client can access servers and printers in any zone on the network. Zones make accessing network resources simpler for users. When users use the Chooser to view the network, they see only the resources in a single zone at a time, preventing them from having to navigate through huge numbers of resources on large networks to find the resources that they need. You can put the clients, servers, and printers used by a single group into a single zone so that users will see only the resources they typically use but will still be able to access resources in other zones when required.

A zone list includes all the zones associated with that network. One of these zones is the network's default zone, to which the Macintosh clients on that network are assigned by default. Users can configure the client to be in a different zone, however.

Working with Seed Routers

When you install Windows NT Server and set up SFM, you must specify whether the Windows NT Server computer will seed each physical network to which it is attached. For example, a computer running Windows NT Server attached to three physical AppleTalk networks might serve as a seed router on two of the networks but not on the third.

For networks that the server will seed, specify the routing information. The Windows NT Server computer will then function as a seed router, seeding the routing information that you provided. If you specify that a server will not seed a network (that is, if you make it a nonseed router), the port will be seeded by another AppleTalk router attached to it.

Using Multiple Seed Routers on a Network

To make your network more reliable in case of system crashes and power outages, you can install multiple seed routers on the same physical network.

When you install multiple seed routers for a particular network, all the seed routers must seed the same information for that network. When the network starts, the first seed router that starts on the network becomes the actual seed router.

When a network starts, if the first seed router to start has different routing information than seed routers that start later, the information established by the first seed router is used. If a seed router that starts subsequently with different information is a server running Windows NT Server, the conflicting information is ignored, an event is written to Windows NT Server Event Viewer, and the server ceases to be a seed router. Non-Microsoft routers might behave differently.

For more information on configuring seed routers in a network, see online Help and the section "Configuring AppleTalk Routing" in Chapter 4, "Routing in Windows NT."

Planning Your AppleTalk Internet

When you plan your AppleTalk internet, follow these guidelines:

  • Determine which router will seed each network. 

  • Decide how to assign network numbers and network ranges. 

  • Decide how to assign zones. 

  • Create a router plan and router record. 

These guidelines are explained in the following sections.

Determining Seed Router Placement on a Network

When planning a large internet, it is helpful to make a diagram of your AppleTalk internet, including the physical network layout and connecting points in the diagram. The following illustration shows an example of an AppleTalk internet. It includes clients only for visual clarity; you only need to diagram routers and servers. Diagramming the internet will help you determine which router will seed each physical network.



Suppose you have an existing network with six computers running Windows NT Server (as shown in the previous illustration). You must determine which server will seed each network. Refer to the illustration as you read the following plan.

  • The seed router for ethernet network #1 must be Server 1, Server 2, Server 3, or Server 4. 

  • The seed router for ethernet network #2 must be Server 4 or Server 5. 

  • The seed router for ethernet network #3 must be Server 5 or Server 6. 

  • The seed router for LocalTalk network #2 must be Server 5, because the router on Server 5 is the only one available for this network. Similarly, Server 3 must seed LocalTalk network #1. 

Assigning Network Numbers and Network Ranges

Follow these guidelines when you decide how to assign network numbers and network ranges:

  • Use network numbers that leave room for expansion. 

    For example, LocalTalk #2 in the Router Seeding Plan Example table, later in this chapter, starts at 1280, leaving plenty of growth for LocalTalk #1, which starts at 1024. 

  • For a LocalTalk network, you can assign only a single network number. For each ethernet or token-ring network, you can assign a network range. 

    Network numbers are essentially arbitrary. The important thing is for them to be unique and to not overlap (if in a range) with other ranges. 

    If you plan to expand any LocalTalk networks for which you can currently assign only a network number, leave a range of unused numbers above the number you assign. You can use these numbers when you expand your network. 

  • Base your network ranges on the number of nodes you expect to have in the future on each network. 

    Base the extent of a network range on the number of AppleTalk nodes expected on the physical network. The total number of possible AppleTalk nodes is 253 times the number of network numbers in the range. For example, a network range of 101 through 103 permits 759 nodes (3 * 253 = 759); a network range of 120 to 129 permits 2530 nodes (10 * 253 = 2530) on a network. Leave room for more nodes than are currently connected. 

Assigning Zones

AppleTalk zones are identified by zone names. Follow these guidelines when you decide how to assign zone names:

  • Assign a single zone name to each physical LocalTalk network. You can assign one or more zone names to each ethernet and token-ring network. An asterisk (*) cannot be a zone name. 

  • For each ethernet and token-ring network, decide which zone will be the default zone. 

  • The number of zones your internet has depends on the size of the internet you are planning. If your internet is small, a single zone can be adequate. But if you have a single Phase 2 ethernet or token-ring network that spans a large geographic area or contains large numbers of AppleTalk devices (such as printers and servers), use multiple zones to make it easier for users to find the devices they need. 

Making a Router Plan

After you have diagrammed your network, make a router plan that shows the location and type of each seed router for the network. The following seed router examples are based on the preceding network diagram.

To make a router plan, determine:

  • The expected number of AppleTalk devices on present and projected ethernet and token-ring networks. 

  • The quantity of network numbers sufficient to satisfy capacity requirements. (Up to n * 253 devices can be supported, where n is the number of network numbers in the range.)

Cable ID

Network range

Zone list

Seed device(s)1

Ethernet #1


Accounts Payable
Accounts Receivable

Server 1
Server 3

Ethernet #2


Marketing Exec

Server 5

Ethernet #3



Server 6

LocalTalk #1



Server 3

LocalTalk #2



Server 5

1 Seed device information can indicate the server name, the type of dedicated hardware router, or the location, depending on your needs. 

2 Indicates the network's default zone. 

Creating a Router Record

To keep information about your internet for maintenance purposes, create a record from your router seeding plan. Include the following information:

  • Router type and version 

    The physical networks connected to the router, with the following information for each:

    • Cabling identification 

    • Network media type 

    • Network number(s) 

    • Zone name(s) 

    • Default zone 

    • Whether this router is a seed router for the networks attached to it 

Note Third-party AppleTalk network management products for Macintosh clients can simplify internet administration. For example, the Apple Inter-Poll® network administrator's utility lets you see all AppleTalk devices (including routers) on an internet in real time, observe every SFM server, and sort devices by network number, device name, node, and so on. If you install the Apple Responder (part of the Inter-Poll product) on Macintosh clients running System 6.x, you can also view those clients with Inter-Poll. (The Responder is built into System 7.) Farallon™ Computing, Sonic System, and Caravelle also provide network management utilities that track network activity.

Preparing to Set Up Services for Macintosh

Before you set up SFM on any computer running Windows NT Server, take the router seeding plans and diagrams you have made, and prepare the information you will need when you install each server. For each server, create a table of information:

  • Indicate the computer name and physical location of the server. 

  • For each network attached to the server, record network ID, network adapter card type, and whether the server will serve as a seed router for the network. 

  • If the server will be a seed router for any network, record the routing information that it will seed for each network, including the network number or network range, the zone name or zone list, and the default zone. 

  • If the server is on an ethernet or token-ring network that has multiple zones, record the zone (or zones) where you want Windows NT Server to appear to Macintosh users. 

The following tables show examples, based on the preceding diagram and examples.

Server Planning Example
Windows NT Server computer name: \\server5
Physical location: Room 1350

Cable ID




Appears in zone

Ethernet #2

EtherLink® II




LocalTalk #2





Windows NT Server computer name: \\server6
Physical location: Engineering Lab

Cable ID




Appears in zone

Ethernet #3

EtherLink II




1 Indicates the network's default zone. 

2 Same as the DayStar Digital card.