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User Guide

Contents


Using LocalTalk (MacIP over AppleTalk)

These directions assume that you will connect to your Internet Service Provider using OT/PPP or Ethernet and want to share this Internet connection with one or more machines via LocalTalk using MacIP (TCP/IP encapsulated in AppleTalk).

First, since IPNetRouter does not provide a full MacIP Gateway, you must set each MacIP interface to "Configure: Using MacIP Manually" (do not select "Configure: Using MacIP Server") in the TCP/IP control panel.

Second, since we are encapsulating TCP/IP in AppleTalk to access machines on a LocalTalk network, you must set AppleTalk to connect to your LocalTalk network. If your LocalTalk network is connected to the printer port of the gateway machine for example, you would set the AppleTalk control panel to "Connect via: Printer Port".

At this point, there are two cases to consider:

  1. You need to configure a MacIP interface using the TCP/IP control panel.
  2. You need to configure a MacIP interface using IPNetRouter.

The first case would arise if you are connecting to the Internet using PPP and do not want to have PPP as the primary interface selected in the TCP/IP control panel. This is important to prevent PPP from making TCP/IP unavailable when the PPP connection closes. In this case, you would select "Connect via: AppleTalk (MacIP)" in the TCP/IP control panel and configure this interface as described below. Refer to the instructions for "Connecting to the Internet using OT/PPP and Ethernet" for details on how to setup an OT/PPP interface using IPNetRouter.

The second case would arise if you are connecting to the Internet via Ethernet using a cable modem and your Ethernet interface needs to get its IP Address using DHCP. In this case, you must use the TCP/IP control panel to configure your Ethernet interface so you can specify "Configure: Using DHCP Server". Since the TCP/IP control panel is being used to configure Ethernet, you will need to configure your MacIP interface using IPNetRouter.

In either case, your LocalTalk network segment needs to have its own range of IP addresses with a unique network number. To follow the addressing scheme of our other examples, we can use IP addresses of the form 192.168.1.x where "x" is a number from 1-254, and use 255.255.255.0 as our network mask. We could assign the MacIP interface on the gateway machine running IPNetRouter 192.168.1.1 for example. Any other machines on our LocalTalk network would be assigned similar addresses ending in .2, .3, .4, etc. so that each machine had a unique IP address. Since the LocalTalk IP interface on our gateway machine is assigned 192.168.1.1, any other machines on our LocalTalk network would use this as their IP router address.

To configure our LocalTalk interface using the TCP/IP control panel, we could enter the corresponding information as follows.

Notice the router address specified in the TCP/IP control panel normally needs to be an IP address on this network, but since we are actually connecting to the Internet via another IP interface (PPP), this router address would just need to be replaced with a "Default-Gateway" (router address) for our PPP interface. Therefore we can just leave the "Router address" empty for now.

To configure our LocalTalk interface using IPNetRouter, we can select "AppleTalk MacIP" in the PortName popup menu, select a unique interface name (ddp0), and enter the desired IP address and subnet mask directly.

Then press "Add" to bring up this interface.

If you are connecting to the Internet using PPP or a second Ethernet interface, it is possible to have both a local Ethernet network and a LocalTalk network. In this case each IP interface on our gateway machine running IPNetRouter has a unique IP address. Following the previous examples, the Ethernet interface is at 192.168.0.1, and the LocalTalk interface is at 192.168.1.1 . Other machines on our Ethernet network will use 192.168.0.1 as their router address, while machines on our LocalTalk network will use 192.168.1.1 as their router address. The correct router address depends on which network a machine is connected to.

In the Routes window above, we have removed the router address (Default-Gateway) that was defined in the TCP/IP control panel (if any), leaving only one Default-Gateway for the PPP interface. This "pseudo gateway" was created automatically by IPNetRouter when the PPP interface was added (since the IP address and mask fields were empty). The pseudo-gateway address is adjacent to the PPP address in the Interfaces window.

Finally, each machine on your LAN (Local Area Network) needs to have a valid Name Server address. This can be the same for all your machines and simply point to one or more Name Servers provided by your ISP.

Additional Notes on MacIP

MacIP over localtalk is not supported in MacOS 9. This is covered in Apple's technote #31211.

Some older Macintosh computers may require MacTCP instead of Open Transport to be used as MacIP clients. Apple no longer appears to offer the MacTCP software for download as of September, 2000. It was included in version 1.1.x of the OT installer and many pre-MacOS 8 Nubus Mac installation CDs.

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