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Apple Macintosh workstations or LaserWriters attached to Ethernet

  Mike Gerard CN/CS

For many years Apple Macintosh systems or LaserWriters came with a built-in port for a small LocalTalk network. These networks tended to be very limited and not enormously rapid. There are currently around 200 such LocalTalk networks at CERN, each of which is connected to the CERN Ethernet via a Shiva FastPath box.

A couple of years ago Apple revised their network protocols to allow connection of Macs and LaserWriters directly to Ethernet, and we are now seeing more and more Macs arriving at CERN with a ready-prepared Ethernet port as well as the standard LocalTalk port.

Unfortunately, the way that the new Apple protocols work involves a lot of network traffic, particularly multicast traffic which has to be sent all over the site. This is particularly bad on a large bridged network such as we have at CERN, and it increases exponentially with the number of such systems connected. In the long term we will deal with this by more use of network routers: in the short term we have to live as best we can with the problems. After various discussions the Telecommunications Board has approved the following guidelines for Macs on Ethernet :-

1.
Where possible, a Mac should be configured to use LocalTalk for all of its AppleTalk traffic (i.e. for printing files on a chosen printer or accessing an Apple File Server). Use of Ethernet for TCP/IP connections such as tn3270, telnet, EDH, MacX and so on is perfectly reasonable.

2.
All Macs which can only be attached to Ethernet (no LocalTalk possible) and all LaserWriters on Ethernet must be put into a zone which best corresponds with the system concerned, The list of such zone names is seen and set in the Network item of the control panel for a Mac: for a LaserWriter it requires the LaserWriter Utility program. Note that the zone name ``Ethernet'' is normally not to be used: it is reserved for certain systems of CERN-wide importance.

3.
A Mac which is attached to Ethernet should in general never offer a file sharing service (i.e. allow itself to be seen as an AFP server) unless this is a service required over the whole of the zone name in which the Mac has been put (i.e. a division or LEP collaboration) by a large clientele. Most of the servers currently seen on Ethernet Macs, using names like ``XYZ's Mac'' will be actively discouraged as from 1994.



next up previous
Next: Plans to ``Rightsize'' Up: General Previous: Coloured Book Software



Janne Saarela
Tue May 16 13:43:26 METDST 1995