🚀 go-pugleaf

In article <3256@soma.bcm.tmc.edu>, dan@soma.bcm.tmc.edu (Dan Johnston) writes:
> 
> We have an ethernet LAN in our laboratory consisting of 5 masscomps, 1 DEC
> LSI 11/23, and several PCs.  We would like to connect our LAN to 
> a similar but larger ethernet LAN at our institution (also running TCP/IP).
> We will need some kind of ethernet bridge or gateway in order to do this, and
> we would like to use one of our masscomps--a PEPed 5500--as this bridge or 
> gateway by running two ethernets from the same machine.  My questions are as 
> follows:
> 
> 1.  Our local sales rep (who is next to worthless on technical questions)
>     says that masscomp has software called "Dual Net" that will do this 
>     and allow us to run two ethernet boards in the same machine.  Has
>     anyone out there heard of this software or had any experience with it?
>     Better yet, has anyone tried to do what we are attempting?  If so, how
>     did you do it?

I have not actually used Dual Net but have had an extensive discussion
with engineering about it.  The software package allows you to connect
one machine to two different networks and access either network from
that machine. *BUT* it does not provide any gatewaying capablities at
all.  If you want to got from a machine on network A to a machine
on network B you must first telnet/rlogin to the Dual Net machine
and then telnet/rlogin to the second remote machine.  In the past there
was good reason why you could not do this, the Excelan [23]01 boards
have the TCP/IP code onboard and the kernel has no easy way to
provide a gateway function, gatewaying is done at the lower IP layer which
the boards do not provide easy access to.  Since the last major
release of the ethernet software (number escapes me) you could run
the Excelan boards in "link-layer" mode meaning that all TCP and IP
processing is done in-kernel.  The Kernel code is based on the
4.2bsd networking code and it supports gatewaying.  BUT Masscomp
for philisophical reasons has disabled this ability and will
not allow gatewaying even for the in-kernel version.  I argued
quite strongly about this but their agrument (though invalid)
is that a user shouldn't use a > $30K machine as a gateway and should
buy a ~$10K dedicated gateway box instead.  Mt argument is that
money doesn't grow on trees and if I can use existing machines
that I already own as a gateway then I should, especially if there
is not *REAL* reason why it won't work.  Having an older 68010
based machine that may not get much use if you have gotten 
68020 or newer 68030 based machines would make a perfect
gateway, instead of having it sit in a corner gathering dust.
At JPL I use an old Sun-2 (68010) that is < 1MIPS as a gateway
because I cannot justify $10K for a dedicated box and all
of our users are using the MUCH faster MC 5600 and Sun-3
machines.  Other groups have 68010 Masscomps that are
gathering dust or even powered off because they cannot afford
an upgrade and users will not use such a slow machine.  These
would make great gateways if they could.
 
> 2.  As part of our PEP package we got a Lance chip on the MPU motherboard.
>     We also have a 201 board on this machine, which we are currently using 
>     for our ethernet.  Does anyone know whether we can use the Lance chip as
>     our second ethernet or do we need to get another 201 board for this 
>     machine?

Theoretically it could (as stated above) but I am unsure if it is
supported.  If you run both the Lance and 201 in in-kernel mode
with the Dual Net it might work.  I suggest you contact MC engineering
for confirmation first though.

If others feel the same way, and do not think that it is a "waste" to
have a Masscomp as a gateway call your local sales rep and complain.
Maybe we can get enough people to call in and get them to support
gatewaying.

> dan johnston (dan@soma.bcm.tmc.edu)
> baylor college of medicine


-- 
	David Robinson		elroy!david@csvax.caltech.edu     ARPA
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