[comp.sys.apollo] Networking Apollo rings together with Cisco router boxes.

jeff@satchmo (Jeff Detterman) (02/01/91)

Has any one had any luck connecting apollo token rings via
Cisco router boxes. Due to the merger of two of our divisions
we need to connect two distinct rings together. The rings
are connected via ethernet, separated by a Cisco router. 
An individual at our company says that this is not possible
but I do not believe him. We would like to run DDS services
between the rings and eventually merge all services (glbd,
rgyd, etc ..). 



Also is it possible to have two rings connected via ethernet 
and token ring back each other up. In otherwords how do I make 
the ethernet take over if the token ring fails. I have assigned
Apollo network addresses to the ethernet and have enabled 
Internet routing on the ethernet gateways. The rings are 
connected via a DN4500 with two token ring cards and via two 
DN4500 that have both ethernet and token ring cards in them. 
Any comments or suggestions would be a great help.

Thanks in advance.




--
Jeff Detterman, Rockwell International, Cedar Rapids, Ia
Email : j_detter@hwking.catd.cr.rok.com

csfst1@unix.cis.pitt.edu (Charles S. Fuller) (02/01/91)

We've been running DDS over cisco routers for some time now, using both
dedicated lines and switched virtual circuits, with minimal problem.
There are a few minor things that you'll run into, but the overall
implementation works quite well.  It has been our experience, though,
that IP data transfers through the same router perform better than 
DDS transfers (eg., ftp vs /com/cpf).

The first thing you'll notice when configuring the cisco is that they
don't provide a node id; you'll have to make one up.  We chose numbers
that are about 3X higher than current Apollo node id's, to avoid
collisions for a little while :-)  Enabling routing is a simple task,
but you'll have to remember when reading the docs that cisco manual
writers have probably never seen an Apollo, let alone configured one.
Between myself and a datacomm guru, we were able to arrive at common
terminology.

Then, once packets start flying, you'll probably want to do an 'lcnet 
-full -hw -conn' -- just to see what you've done.  The first thing
you'll see is an error message to the effect that the node identified as
the cisco did not respond, and that "touching" information may be
incomplete.  This is not an indication of problems, but, rather, an
indication that cisco routers lack the ability to respond to
"higher-level" DDS queries (like 'lcnet'). 

When combining networks, be sure to give some thought to administrative
issues, most importantly the registry.  There are 7 different registries
in our network, some of which span multiple sites.  Some are SR10, some
SR9.7.  We found out early on that, despite documentation to the
contrary, it is not necessary to merge registries UNLESS everyone needs
access to every machine.  If your sites are to remain autonomous, you
may want to leave the registries separate.  This also provides a little
extra protection from users at other departments, although root is
always root, capable of walking through the entire network.  Keeping
registries separate became a little difficult at SR10.0 and SR10.1, but
the addition of NCS cells at SR10.2 made registries a little more
manageable once again.

Hope these ramblings are of some use.
Chuck

jab0396@cec1.wustl.edu (John A. Breen) (02/03/91)

In article <86164@unix.cis.pitt.edu> fuller@nye.nscee.edu (Charles S. Fuller) writes:
>The first thing you'll notice when configuring the cisco is that they
>don't provide a node id; you'll have to make one up.

It's been a while since we hooked up to the ethernet (and I had
retired from sys-adminning just before that, so I just watched), but
as I recall, the ciscos were pretty much transparent (they were
already set up for general ethernet connections).  I think we just
assigned network IDs to each ring and one to the ethernet as a whole,
and that was it.  In fact, I remember when we enabled routing, we saw
a network we didn't recognize: it turned out to be a ring at one of
our facilities on the west coast (although that did cause a minor
problem, since they had assigned a different network ID to the
ethernet).  But from the Apollo filesystem point of view we've had
virtually no problems.

Now, subnetting for TCP/IP is a different problem; some day I'll have
to relate that horror story...

John A. Breen
McDonnell Douglas Missile Systems Co.
-----------------------------------------------------------------------------
John A. Breen                |     "Where is fancy bread,
    jab0396@cec1.wustl.edu   |         in the heart or in the head?"
    johnb@hobbes.mdc.com     |                   -- Willy Wonka

mort@apollo.HP.COM (Stephen Moriarty) (02/07/91)

In article <1991Feb1.000434.244@zoot.avgrp.cr.rok.com> jeff@satchmo (Jeff Detterman) writes:
>Also is it possible to have two rings connected via ethernet 
>and token ring back each other up. In otherwords how do I make 
>the ethernet take over if the token ring fails. 

        A lot of people ask for this. You can't do it. The reason
is that the registries/naming servers are fixed, and can only be
changed explicitly. What you're asking for is that the naming
server be dynamic, trying different net.nodeid pairs upon failing
to access on. The `node_data/hint_file comes into play, as well,
since that's where you get your net.nodeid pair after accessing a
node for the first time. If you consult Chapter 7 of, "Managing
Domain/OS and Domain Routing in an Internet" for "How to move a
node from one network ID to another", you'll see what needs to be
done dynamically in more detail.

mort

ARPA: mort@apollo.hp.com        UUCP: ...{decvax, umix, mit-eddie}!apollo!mort
Apollo, a subsidiary of Hewlett Packard, 300 Apollo Drive, Chelmsford, MA. 01824
              Argue for your limitations, and they are yours.