3COM EtherLink: Running AppleTalk and EtherTalk Concurrently



Regarding the concurrent use of AppleTalk and EtherTalk:

I have 3COM's EtherLink/NB interface cards using EtherTalk and running 3COM's
3+Share for the Macintosh. Here is my procedure:

1) I log on to the Internet Server using the Chooser. (The CDEV is set to
EtherTalk.)

2) I link the appropriate Servers, printers, shared folders, etc.

3) I change the CDEV back to LocalTalk, and a warning dialog box appears
telling us that we will lose our current connection. Choose OK.

4) I go back to the Chooser and select a LaserWriter from the AppleTalk
network.

5) I still have an EtherTalk connection! I haven't lost anything, and
AppleTalk is active.

I have always thought that a workstation could use only one AppleTalk
connection at a time (although it may be physically connected to several
networks, sending and receiving data over the selected network connection).

Why and how does this 3COM EtherLink continue to work? Doesn't the LAP Manager
send packets to the connection selected in the Control Panel?

As a user, you can have access to only one physical network at a time through
the link access you specify via the Control Panel.

During tests, when we change our network device in the Control Panel, we do
lose our connections to our network services. We suspect that the 3COM
software is not actually using AppleTalk, but instead is implementing its own
protocol stack, which bypasses even the LAP specified by the Network Control
Panel device.

If this is the case, then only the AppleTalk-based services would be lost whil
all of the 3COM services would remain unaffected including the servers. This
would mean that you actually don't have EtherTalk, but you do have the 3COM
Ethernet connection still up and running.


Published Date: Feb 18, 2012