AppleTalk-IP Decapsulation and AppleTalk-IP Encapsulation¶
Documentation ipddp.c
This file is written by Jay Schulist <jschlst@samba.org>
Introduction¶
AppleTalk-IP (IPDDP) is the method computers connected to AppleTalknetworks can use to communicate via IP. AppleTalk-IP is simply IP datagramsinside AppleTalk packets.
Through this driver you can either allow your Linux box to communicateIP over an AppleTalk network or you can provide IP gatewaying functionsfor your AppleTalk users.
You can currently encapsulate or decapsulate AppleTalk-IP on LocalTalk,EtherTalk and PPPTalk. The only limit on the protocol is that of whatkernel AppleTalk layer and drivers are available.
Each mode requires its own user space software.
Compiling AppleTalk-IP Decapsulation/Encapsulation¶
AppleTalk-IP decapsulation needs to be compiled into your kernel. Youwill need to turn on AppleTalk-IP driver support. Then you will need toselect ONE of the two options; IP to AppleTalk-IP encapsulation support orAppleTalk-IP to IP decapsulation support. If you compile the driverstatically you will only be able to use the driver for the function you haveenabled in the kernel. If you compile the driver as a module you canselect what mode you want it to run in via a module loading param.ipddp_mode=1 for AppleTalk-IP encapsulation and ipddp_mode=2 forAppleTalk-IP to IP decapsulation.
Basic instructions for user space tools¶
I will briefly describe the operation of the tools, but you willneed to consult the supporting documentation for each set of tools.
Decapsulation - You will need to download a software package calledMacGate. In this distribution there will be a tool called MacRoutewhich enables you to add routes to the kernel for your Macs by hand.Also the tool MacRegGateWay is included to register theproper IP Gateway and IP addresses for your machine. Included in thisdistribution is a patch to netatalk-1.4b2+asun2.0a17.2 (available fromftp.u.washington.edu/pub/user-supported/asun/) this patch is optionalbut it allows automatic adding and deleting of routes for Macs. (Handyfor locations with large Mac installations)
Encapsulation - You will need to download a software daemon called ipddpd.This software expects there to be an AppleTalk-IP gateway on the network.You will also need to add the proper routes to route your Linux box’s IPtraffic out the ipddp interface.
Common Uses of ipddp.c¶
Of course AppleTalk-IP decapsulation and encapsulation, but specificallydecapsulation is being used most for connecting LocalTalk networks toIP networks. Although it has been used on EtherTalk networks to allowMacs that are only able to tunnel IP over EtherTalk.
Encapsulation has been used to allow a Linux box stuck on a LocalTalknetwork to use IP. It should work equally well if you are stuck on anEtherTalk only network.
Further Assistance¶
You can contact me (Jay Schulist <jschlst@samba.org>) with anyquestions regarding decapsulation or encapsulation. Bradford W. Johnson<johns393@maroon.tc.umn.edu> originally wrote the ipddp.c driver for IPencapsulation in AppleTalk.