classiccmp-digest V1 #927

From: Chris <mythtech_at_mac.com>
Date: Sun Apr 21 23:13:24 2002

>> Will a Dayna EtherPrint-T work for connecting, say, a LocalTalk Mac into an
>> EtherTalk network, or does it only work for printers? In other words, is it
>> a true LocalTalk-to-EtherTalk bridge?
>
>I don't think the Mac supports encoding/decoding TCP/IP packets via
>localtalk. From what I understand Ethertalk (what mac compatible
>printers talk on ethernet) is essentially localtalk wrapped with an
>ethernet packet. :-/ TCP/ip is a different protocol on the same
>computer and that is only supported through PPP(remote access) and ethernet.

These are actually two different things.

1: Localtalk bridged to EtherTalk (appletalk over ethernet). That is what
the Dayna box does. It is good only for AppleTalk uses (file sharing,
printer sharing...).

2: TCP/IP over Appletalk. That is known as MacIP. AppleTalk does not
natively carry TCP/IP, so a localtalk to ethertalk bridge will not pass
TCP/IP simply because TCP/IP can't exist on localtalk (well, I won't say
can't, but isn't done with any native Apple hardware). However, you CAN
use MacIP, which is Apple's answer to TCP/IP over Appletalk. That is
TCP/IP wrapped in an AppleTalk packet. That will be passed by a Localtalk
to Ethertalk bridge, simply because the bridge won't know it is not
Appletalk.

The problem you get into with MacIP is you need something to unwrap it on
the other end and pass it to the internet (or whatever TCP/IP application
you are using it for). MacIP doesn't work as straight TCP/IP.

If you are looking to do localtalk with TCP/IP, a much better solution is
to find an old 030 or better box with ethernet (LC2 or 3 works great),
and run Sustainable Softworks' IPNetRouter. They have a MacIP router
built into it. Then, run Apple's LaserWriter Bridge if you ALSO want to
route straight Appletalk using the mac based bridge (IPNetRouter will
only examine the MacIP portion, so it won't pass a regular appletalk
connection for things like Appleshare, file sharing, and printer sharing,
as a result you need Apple's free LaserWriter bridge, which the newest
version (2.??) IIRC will bridge for a full appletalk network and not just
printers).

I would also guess that older versions of AppleShare Server might have a
MacIP router built in. Apple must have offered a solution for it, I can't
believe they would provide all the client end tools and not have some way
of unwrapping it other than depending on a 3rd party program (which is
the only app I have seen that does it, but I am sure there must be
others).

-chris

<http://www.mythtech.net>
Received on Sun Apr 21 2002 - 23:13:24 BST

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