Networking TIC

Appendix C - How to Configure Ripro Server AppleTalk

• Overview
• A Site with No AppleTalk Router
• A Site where the Ripro is an AppleTalk Router
• A Site with an External AppleTalk Router
• How the Ripro selects an AppleTalk address
• How a Mac selects an AppleTalk address

Overview

Throughout this section of the TIC, AppleTalk refers only to AppleTalk Phase 2.

Sub-network refers to the third layer of the seven layered communication stack sub network. This Sub Network can be segmented by a Switching Hub or Bridge (layer two network segmentation).
For example, When a server is connected with FDDI to a switching hub with 16 Ethernet ports, all 16 Ethernet segments and the FDDI are considered as being one sub network.

The Ripro Server can support AppleTalk on a single or multiple network interface, Ethernet and/or FDDI.

When AppleTalk is configured on a multiple network interface, the Ripro Server acts as a router, and publishes network numbers (physical cable range) and zones on the network.

When only one network interface is configured, the Ripro acts almost like any other AppleTalk device such as a Mac or LaserWriter, etc. However, the Ripro does not fully support dynamic AppleTalk address configuration.

The AppleTalk address contains three numbers:
Net#, Node#, and Socket#.

Net Number can range from 1 to 65534,
Node and Socket numbers may take on a value from 1 to 253.

On the Ripro Server, the AppleTalk Network Numbers (cable range) and the Zones need to be configured. This procedure is described below.

The netconf util on the server is used to configure AppleTalk on the Ripro server.
Three different configurations are supported:
· A site with an external AppleTalk router.
· A site with no AppleTalk router.
· A site where the Ripro is the AppleTalk router.

A Site with No AppleTalk Router

When the Ripro acts as an AppleTalk device (no routing activity), the interface that runs the AppleTalk should be configured like the FDDI in the following example:

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AppleTalk Network Setup, press CTRL-D to end

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The meaning of this setup is:

• The Ripro is connected to the network without a router.
• The Ripro can talk directly (not via a router) to any other AppleTalk node on any network number (1-65534).
• There are no zones on this network ( on the MAC the chooser has only two windows).
• The Ripro will try to register itself as Network No. 1 and Node No. 140 (1.140).

Note: Since the Ripro is not a router, the Ripro cannot publish zone names on the network. Configuring zone names in this case is illegal and will cause problems on the network.

A Site where the Ripro is an AppleTalk Router

The Ripro acts as an AppleTalk router when more than one network interface is configured to run AppleTalk.

The netconf screen should be, for example, as follows:

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AppleTalk Network Setup, press CTRL-D to end

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The meaning of this setup is:

• The Ripro is an AppleTalk router.
• There are at least two AppleTalk Sub Networks at this site (more are possible is there is an external router connected to one of the Ripro interfaces- In this case see "A Site with an External AppleTalk Router" for information how to configure the interface that is connected to the external router).
• The Macs (or any other AppleTalk device) connected to ent0 (the first Ethernet board on the server) are in Sub Network 12-14 and on zone A. If additional zones are configured on et0 they can also choose one of the additional zones. The Macs (or any other AppleTalk device) connected to fi0 (the first FDDI board on the Server) are in Sub Network 25 and on zone ZoneB. If additional Zones are configured on fi0 they can also choose one of the additional Zones.
  It is possible to configure the same zone name on more then one interface, in this case AppleTalk devices on different Sub Networks can share the same Zone name.
• In case the Ripro is connected to a second Ripro server that is configured as a router, you should relate to the second Ripro as an external router.
• Any AppleTalk device on Net 12-14 that talks to an AppleTalk device on Net 25 (or vice versa) sends the data (packets) to the Ripro and the Ripro forwards it to the other Device (routing).
• The Ripro publishes himself (AppleShare Server and Printer Spoolers) on the first Interface and Zone configured, in this example the Ripro will be on ZoneA.

Note: Do not connect two interfaces of a Router to the devices that bridge them.

For example: configuring AppleTalk on two Ripro interfaces that are connected to the same switching Hub is not allowed and will cause severe problems on the network (i.e. devices jumping from one zone to the other, lost connections, etc.).

A Site with an External AppleTalk Router

If the Ripro is connected to a network with an external router, the Ripro should be configured according to the configuration of the external router.

For example, an external router has 2 interfaces and the Ripro is connected to interface 1 of the router. The external router was configured to publish the following network information on interface 1:

The Ripro configuration should then look as follows (assuming that the Ripro is connected via FDDI):

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AppleTalk Network Setup, press CTRL-D to end

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The meaning of this set up is:

• The Ripro is connected to a network with an external router.
• The Ripro can talk directly (not via the router) to any other AppleTalk node that is on the same Sub Network (4-5).
• The Ripro can communicate with AppleTalk devices that are connected to other interfaces of the router via the router. The Ripro will send the data (packets) to the router and the router will forward it to the appropriate interface (and vice versa).
• The Ripro will try to register itself with Network number 4 , Node no. 140 (4.140).
• The Ripro will publish itself on zone Nirvana.
• The zone list for the Ripro should be identical to the zone list of the router interface that the Ripro is connected to.

How the Ripro selects an AppleTalk address

The Network Number is set for each interface that is running AppleTalk according to the netconf configuration. The Ripro tries to use the Network Start number.

The Node number is set as follows (assuming that the Network Numbers are 1 2):
The Ripro will try to use 140 as the node number. If any other station already uses this address, the Ripro will try 141 as the node number and so on, until it finds a free node number on this Sub Network. If all the nodes from 1.140 (Net #.Node #) to 1.253 are in use, the Ripro will try 2.140 and higher (there are almost no chances that this will happen even in a network with a lot of Macs).

How a Mac selects an AppleTalk address

The Mac configures the network and node numbers dynamically. First, it will try to use the same address it had the last time it was connected to the network. If this address is taken, or the network configuration was changed and the address does not fit the new configuration, the Mac will pick another address (pseudo-dynamically).