BALAMUT%OLYMPS@engvax.scg.hac.COM ("Morris Balamut - The Dungeon Master 513-5829", 213) (03/17/88)
I tried sending this several weeks ago and have not see it or 'heard'
any discussion on it so here it goes again. Sorry for any inconvenience
if you received it twice.
----------------------------------------------------------------------------
I want to talk about attaching Apple Macintoshes to ethernet. There has been
various discussions about this subject and the problems associated. My
company has a very large ethernet that connects all of its major sites in
southern California. I have some thoughts on the subject and I would
like to get some feedback and/or information.
Until recently we have not had too much problem with Macintoshes connecting
to the ethernet. We have established a basic policy that the connections
must be through a gateway such as an Kinetics FastPath. The problem we
are developing is that with the advent of MAC IIs the number of users
who wish to connect their equipment directly to the ethernet using
one of the various ethernet cards. These users want to use the ethernet
to take advantage of the higher bandwidth data transfers that will be
available as compared to LocalTalk.
The AppleTalk protocol addressing scheme can only allocate 254 addresses
on any AppleTalk network. This results in a maximum of 254 nodes on an
AppleTalk network running on ethernet.
This introduces a problem, we have a VERY large ethernet quite a few Macs
and the number of Mac IIs are growing. In addition many Mac SEs & PLUSs
are clamoring to get on the ethernet. We are faced with the limit of
254 Apple/EtherTalk devices on the ethernet. I trust the problem is
obvious.
The reason for the limit as I see it is that you can not run multiple
network numbers on the ethernet. The problems stems from the inability
of the information from one network to find its way to the appropriate
destination (socket). It would seem that if there was an router of
some kind on the ethernet to provide the name service and routing
for multiple network numbers then we could easily exceed the limitation
of 254 devices.
The limitation is also on a per ethernet basis. The way we have our
ethernet hooked up it is logically one ethernet. I would guess that
another possible solution would be to have a 'protocol router' that spoke
AppleTalk inserted between the main ethernet backbone and the subnets
to provide logical isolation. I equate this to the way InterBridges
allow you to expand a LocalTalk network.
Does anyone have any suggestions for implementing any of the above or
has an alternate solution.
Morris Balamut balamut@olymps.hac.com
Network Support Group balamut%olymps.hac.com@oberon.usc.edu
Hughes Aircraft mbalamut@ecla.usc.edu
---------------------------------------------------------------------------
Disclaimer: The preceeding represents the random hallucinations of my fertile
imagination and may not reflect the opinions of my boss or my
boss's boss.