To what extent should we use DNS?

[aaron@sdt.com (Aaron Gair)]

DNS or not to DNS ( partial, full, limited, special implementations )

SCOPE
=====

Our company SABRE Decision Technologies ( American Airlines ) has recently
decided to obtain a direct Internet Connection.  We currently use UUCP
for mail and news.  The cost associated with UUCP is driving this 
direct Internet connection ( of course we are excited about the other
benefits too ).  Our group of network and UNIX guys have agreed that 
a firewall will exists.  Our environment is a large UNIX development
shop consisting of several UNIX platforms.  We have approximately 20
large compute servers, 200 workstations, and 150 xterminals.  We also
have a large PC, MAC, and OS/2 environment, of which a small amount
use X emulators.  We have a CLASS B IP network that is subnetted.
The network is divided into 24 ethernet segments and rapidly growing. 
The network utilizes CISCO routers and synoptics gear.  A typical developer
in our environment must rely on NFS, X, routing, mail services, access
to DBs, communication gateways, and various compute servers.  All 
resources are spread out over the network.

Secondly, we need to communicate with other UNIX pockets within American  
Airlines.  Currently all UNIX environments use /etc/hosts and 
propagate the new file to all hosts in their own UNIX environment.  
The update between UNIX pockets is done manually.

Our last, but equally important, consideration is our customer base.  Since
we develop UNIX apps - our clients run UNIX networks.  Not many run 
DNS, however who knows what is around the corner.  We have external
links to a small portion of our customer base for maintenance reasons.

By the way, our company currently has 650 employees and will grow to 2500 
by the end of 1994 because of a company merger. We are also opening
marketing offices with demo facilities all around the world.  Some of
our work is performed at client sites on soon to be UNIX production 
machines.


DECISIONS??
===========

In our local UNIX environment - hosts file maintenance is very simple.
We make a change on one server - rcp to others - poof!  After 
investigating the technical details of DNS, we realize that using
DNS all over our environment is going to turn a very simple thing
into a complex monster.  We won't even mention the reliability factor.
We also are constantly making changes and moving machines.  It is
our understanding that DNS, and all of its choice parameters, does
not make changes apparent to ALL immediately.  Once we hook up to 
the Internet we will either setup iftp and itelnet or force users
to use an ftp/telnet/other server.  

Given the above scenario, what would you do?  Are there things in 
the near future that we should be aware of when making decisions about 
how DNS fits in our environment?  What concerns should we have?  What 
pros/cons can we expect out of the different DNS options? We desperately 
need some suggestions and recommendations in regards to DNS and our 
environment.  

Thanks in advance,

Aaron C. Gair
aaron@sdt.com
(817) 931-1656
Ft. Worth, TX US of A