Path: utzoo!attcan!uunet!timbuk!cs.umn.edu!sec
From: sec@cs.umn.edu (Stephen E. Collins)
Newsgroups: comp.protocols.appletalk
Subject: Re: Campus AppleTalk Internet Strategies
Message-ID: <1990Oct23.015216.22601@cs.umn.edu>
Date: 23 Oct 90 01:52:16 GMT
References: <722@casbah.acns.nwu.edu>
Organization: University of Minnesota, Minneapolis, CSci dept.
Lines: 69

jln@casbah.acns.nwu.edu (John Norstad) writes:

>At Northwestern University we are currently experiencing explosive growth 
>in both our IP and AppleTalk internets.  We have several dozen IP networks 
>joined together with Cisco routers and PC routers, plus several dozen 
>AppleTalk networks.

You ought to visit your alma mater and see your future.  We're also
experiencing explosive growth in networking on campus (isn't everyone?).
We currently have well over 100 AppleTalk zones on campus, with
around 200 FastPaths (a single zone can share several FastPaths).  We
have experimented repeatly with the GatorBox, but without success.
(Their Tech support people always give up after a while; seems to be
a problem with our large & strange network).

We also have more IP networks than I care to count.  The main
backbone is segmented with Cisco routers for IP (and other) traffic,
and has Apple Routers running in parallel with the Cisco routers
to handle AppleTalk traffic.  I wasn't involved with testing
the Cisco AppleTalk support, but I seem to recall that Cisco routers
and AppleTalk traffic didn't get along very well.

>My problem is that I'm beginning to worry about various limits in atalkad. 
>According to my ancient KIP documents, and according to the output of 
>atalkad -c, I'm approaching some of these limits.  The documented limits 
>are 256 bytes for all zone names (I'm up to 191 bytes), 32 zones (I'm up 
>to 16), and 64 routes (I'm up to 27).

>My first question is:  Are these limits absolute?  Is there any way to 
>increase them?

Most of these limits have increased quite a bit in the new FastPaths.
Also keep in mind that you can set up a FastPath to configure itself
dynamically; they don't all  have to be in your static routing table.
We try to limit the static routing table to only those FastPaths which
are pointed to by CAP servers or need to be there for some other
specific reason.  The rest are dynamic.

>My second question is:  What are the reasonable alternatives to atalkad 
>tunneling for building a large campus AppleTalk internet?  I know that 
>Cisco routers can do AppleTalk routing, but PC Routers can't.  Replacing 
>all of our many PC routers with Cisco routers would be very nice for many 
>reasons, and we'd all like to do it, but it's just too expensive.  
>Replacing all of our FastPaths by Gatorboxes or vice-versa is also out of 
>the question.

Also consider the Apple Router as I mentioned.  It's a cheap solution
for routing Appletalk packets on your IP network; it's been working
well for us for quite a while.  I'm not sure about the current state
of the Cisco AppleTalk package.  I'd also watch the GatorBoxes carefully
as your network grows.  We never figured out quite what the problem was
on our campus.  The GatorBox would run fine for a day or two, and
and then hang up.

>I know that other universities have very large AppleTalk internets.  How 
>do you do it?

I hope I gave you a few leads; feel free to contact me if you want
any more information.  If you ever visit your old homestead, drop in
and we can give you a tour.

>John Norstad
>Academic Computing and Network Services
>Northwestern University
>jln@casbah.acns.nwu.edu

Stephen E. Collins
University of Minnesota Microcomputer & Workstation Networks Center
sec@boombox.micro.umn.edu | sec@umnacvx.bitnet