From: brianb@wc.novell.com (Brian Bulkowski)
Subject: Re: Novell servers running Internet Router
Organization: Novell Inc.
Date: Sat, 5 Sep 1992 00:27:27 GMT

Hi,
The real reason we designed it this way was two fold:
1) It was a heck of a lot easier to do in the time we had with the
tools and source code bases we had. We had the AppleTalk router
from the fastpath, we had (ancient, I've heard they've cleaned it up)
Portable AppleTalk code from Apple. We had to mate the two together,
an internal net was ideal.
2) To protect administrators from themselves. If AppleTalk homes on
a particular card, then all AppleTalk services are slave to that card
and network being up. By homing on an internal net, we can keep AppleTalk
services up as cards are bound and unbound, as configuration changes.

Since we realize that this isn't an ideal situation, a future release
will include the ability to run without the router. Another configuration
will allow routing, but the stack will be homed on a particular interface.
But it was the best we could do at the time.

WRT your feeling that the extra routers slow down a net - I don't think
this is a real concern, unless you run with localtalk backbones. Even with
50 nets, that won't even get you three packets. Thus, for each router you
generate 3 packets every 10 seconds, even without split horizon. If you had
10 servers on a backbone, we're talking 3 packets per second without split
horizon, and probably 1 packet per second with. With NBP and all your servers
in the same zone, things get a bit worse, since a FwdReq will be generated
for each server, but if you split your zones humanely you wouldn't incur
more than a few extra packets per lookup. With ZIP the only extra traffic
is when a net goes up or down.

The main reason that we found for everyone hating "router on always"
was that a network number had to be assigned for each server. Thus, the
far flung server, under some strange administrator, had to be more closely
tied into the network administration. This is our main motovation for
moving to the no-router case. I think the other problem, that people don't
want extra router on their network, is based in fear of the unknown rather
than real technical problems. I know of a network far worse, with about
50 Novell AppleTalk servers ON ONE NETWORK on ethertalk with T1 *repeaters*
between the ethernet segments. 1200 devices in one network. And it works,
mostly, and RTMP, ZIP, and NBP from the extra routers are the least of 
their worries.

BTW, I find the terminology of "Novell Internet Router" confusing. Any
router is, by Apple definition of the word, "Internet". It routes between
two nets. However, it confuses with the Apple Product "Apple Internet Router",
aka AIR. So, "AppleTalk Router" should be sufficient.

I hope this clears up any confusion, and shows that Novell is answering
the demands of the marketplace in this regard. We hear you!

BrianB
AppleTalk transport project lead
brianb@wc.novell.com

In article <1992Sep3.043801.24066@gatech.edu>, shahid@oit.gatech.edu (Shahid Sheikh) writes:
> 
> Hi netters
> 
> Can someone explain why a Novell Server has to run an AppleTalk Internet
> Router in it. I know it runs one for IPX as well. But is there a real true
> reason why it has to run the router for appletalk. It seems kind of silly
> just to run an Internet router for one server and not being able to connect
> any devices on the Appletalk subnet. Moreover, if you have about a hundred
> routers already existing and you put like another 50 Novell servers on your
> network, wont that significantly increase your RTMP and ZIT tables and slow
> down the network?
> 
> The response I've got from Novell so far is that they have designed the
> multiprotocol support according to the ODI specifications which requires
> them to run that router. Since when appletalk devices have to be designed
> according to ODI standards? Is there a way around this router other than
> not using the stupid Novell server at all? What kind of remote management
> tools come with the Novell router? Does it support SNMP? Can I monitor and
> control the router from a remote non-IPX device?
> 
> Any information would be greatly appreciated.
> 
> Shahid Sheikh
> Network Services -- Georgia Tech
> shahid@oit.gatech.edu
> 
>