David Strom

TCP/IP For Virgins

By David Strom

TCP/IP may be the lingua franca of the computing world, but you'll need the networking

equivalent of the Rosetta Stone to be able to install, configure, and maintain a network of

mixed client operating systems. Getting a Macintosh, a Windows PC, an OS/2 client, and a

NetWare server to all speak the same language won't be easy, even for experienced


There are several reasons for these difficulties: TCP/IP's heritage is with Unix, and non-Unix

clients don't necessarily have the operating system depth needed to work well with this

protocol. Many of the products have documentation that is obtuse and not geared towards

beginners. Sorting through the many product options will take time and many calls to vendor

representatives to understand what is needed in any particular configuration. All of the

products required an intimate understanding of not only the client operating system but the

way protocols are loaded by that operating system and other subtleties of the particular

software products.

In addition, product pricing is confusing to calculate, depending on the particular software

options and user licenses required.  And speaking of user licenses, the TCP/IP software

market reflects its strong Unix bias: many of the products come with cumbersome software

keys and other methods that have been long since abandoned by more enlightened PC

software vendors. 

These conclusions are based on a series of tests done on a network with four machines: three

clients (Windows, Macintosh, and OS/2) and a NetWare 3.11 server.  We chose a typical

software product for each computer: NetManage's Chameleon for Windows, InterCon's

TCP/Connect II for the Macintosh, IBM's TCP/IP for OS/2 and Firefox's Novix for NetWare.

Novix offers support for both DOS and Windows clients attached to NetWare servers as part

of their package. (See sidebar for pricing and contact information.) We did not consider any

freely-available shareware, mainly in the interest of limiting the scope of our research to

make it more manageable. We used Compaq and Dell PCs for both clients and our NetWare

server and a Macintosh IIvx. All machines had at least 8 megabytes of RAM installed. 

Two testing scenarios examined

We examined two scenarios: first, TCP/IP was used as the primary means of cross-platform

communication among the various clients on a single Ethernet segment.  This configuration

tested the File Transfer Protocol (FTP) software of  each product, and the ability to use

various diagnostic utilities.  Second, we attached a modem to each client machine and tested

how the TCP software could connect via Serial Line IP (SLIP) protocols to communicate to

the ANS dial-up service bureau. This configuration tested the scripting features, the bundled

mail and network news readers and the ability to switch between Ethernet and SLIP

configurations easily.


Our goal was to determine how difficult it is to install and use the various TCP/IP software

programs for each product. We also judged the relative complexity of each configuration and

compared this with the ease of connecting each client to a NetWare server.

Understand your plumbing

First off, you'll have to understand what plumbing is installed, and what you might be

missing. Merely connecting each computer with an Ethernet card and cabling isn't enough.

Network administrators have several other factors to consider:

--Ethernet frame types. Typical Unix computers use Ethernet frame type II, which differs

from what most PCs and Macs use (type 802.3 and type SNAP, respectively). Our test

network, which had no Unix machines, worked mainly because of our NetWare server which

bridged the various frame types internally:  A NetWare server can support multiple frame

types over a single network adapter quite easily, through the additional commands in its

startup files. Macintoshes are limited to supporting a single frame type per network adapter,

while DOS and Windows PCs and OS/2 can support multiple frame types in their

configuration software. 

-- running multiple protocols on the client. Most corporate networks can't get by with running

just TCP/IP on their networks, and will need to support additional protocols such as IPX or

AppleTalk. In this situation the Mac excels, since setup is similar for each protocol and

various servers appear as similar icons on the desktop. 

For both Windows and OS/2 there are two separate schemes for PC multiple protocol use: the

Network Driver Interface Specification (NDIS) championed by Microsoft, and the Open

Datalink Interface (ODI) specified by Novell.  Chameleon for Windows, along with most

OS/2 software including the TCP/IP client from IBM, all use NDIS  to load multiple

protocols. This makes configuring any OS/2 clients and Chameleon a cumbersome job to

support the IPX protocols necessary to talk to a NetWare server. 

The install procedures for both Chameleon's and IBM's products requires users to manually

modify their PROTOCOL.INI file, which is where IPX protocols get loaded in the NDIS

scheme. Basically what this amounts to is loading NDIS at boot, then loading the necessary

ODI support: it is tricky and will require some experimenting to get it working correctly.

NetManage officials indicated that they will directly support Novell's ODI scheme for loading

multiple protocols in the next version of their software.

Novix gets around the entire multiple protocol issue by running an IPX to TCP/IP gateway in

the NetWare file server. This removes from the client any need to run more than IPX

protocols. However, users must manually adjust their NET.CFG file to support Novix's client

software, which was just as cumbersome as NetManage's to configure.   

-- support for token ring networks. Some of the products don't do a particularly good job of

supporting token ring networks: again, that Unix/Ethernet heritage runs deep. Novix only

recently added such support, TCP/Connect doesn't include it at all, Chameleon and IBM's

OS/2 software use NDIS, which makes for wider token ring support. These last two products

offer a limited number of card choices during installation. However, if you have the NDIS

drivers for your adapter, you can install them manually. 

-- understanding IP addressing. No foray into the world of TCP/IP would be satisfactory

unless one understands the rudiments of IP addressing. While this could easily be a subject by

itself, there are several key elements that beginners should understand. First, by all means

obtain from the InterNic (info TK) a legitimate series of IP addresses, and then assign each

one from a central place in your organization. Each address has to be unique, otherwise all

sorts of networking mischief will result. Second, realize that the addresses reflect the

underlying networking infrastructure. If you have a single network segment, then the first

three numbers of each address should be the same (each IP address is composed of four

numbers, the third number in the sequence indicating the particular network segment, and the

fourth indicating a particular computer on that segment). Finally, if you have multiple

segments, routers, or other complexities, you'll need to really understand your topology and

where each machine will be placed in the network before you configure the software of each


-- diagnosing problems. The world of TCP/IP has an almost universal diagnostic tool called

Ping, which tests the link between two computers. All of the products except TCP/Connect

included this software, and it is fairly simple to use: you merely type in the IP address or the

name of the computer you wish to test. You will then receive a display indicating whether or

not your test packets were received by the intended computer, and how long (in milliseconds)

the journey took. A second tool is to run the VT220 emulator: while it doesn't make sense to

use a terminal emulator with a non-Unix client, generally if the emulator would load without

errors, you can be assured that your client software has been configured properly.

Switching configurations between LAN and SLIP

A second issue is how easy is it to specify various hardware configurations and switch

between them. In our tests, we used two basic configurations: Ethernet and SLIP connections.

InterCon's TCP/Connect on the Mac was the easiest to change configurations: a simple

check-off box with the usual Macintosh icons makes this a quick task. Chameleon's Windows

client software has a bug which makes this switch somewhat cumbersome: users must first

change to a new configuration, save it, exit the software, then finally reload the software. 

IBM's OS/2 allows up to one SLIP connection and eight different network adapters to be

configured, showing OS/2's strengths in handling multiple connections. The other products

can have a single connection active at any one time.

One of the niceties of each of the software packages is the ability to automate the login

process, especially helpful for SLIP connections to Internet hosts where you have to enter

user names and passwords. IBM uses REXX, the procedural command language that is

built-in to OS/2, for this scripting: if your users have already learned it, this is a plus. Novix's

LAN Workplace software and NetManage each have their own scripting language. Both are

relatively simplistic and would benefit from more examples and clearer documentation.

TCP/Connect doesn't offer any scripting features, although users can specify up to ten

different text strings which can be used during a Telnet login session. 

Speaking about connecting to the Internet, we found it handy to already have an Internet

connection in place: many of the patches, fixes, and helpful suggestions are available via FTP

from many sources.  

Using various applications: FTP, Telnet, News, etc. Figuring out which applications are part

of the base package and which are extra-cost options is almost as difficult as pricing

automobile options. Each vendor offers a different scheme. For example, InterCon has four

different product options: the base package includes FTP client and server, and Telnet

emulation for three terminal types. Additional options are available for Mail and News

readers, printing, and SLIP. Chameleon and Novix offer the widest product options as part of

the base package.

With Novix, you don't have the ability to turn a NetWare server into an FTP server: that must

be done at the individual workstation. Software from Novell called Flex/IP does do that.

Other products were fairly easy to setup as FTP servers: they typically had a single check box

or menu item that would enable other users to connect and transfer files.


Despite these drawbacks, TCP/IP makes sense for connecting different clients  operating as

peers, even when none of the clients runs Unix. However, getting TCP connectivity up and

running is more of a beginning, rather than an end: users will still need to configure

applications such as cross-platform printing, NFS for file sharing, and others.  Some of these

applications are included as part of the base package (such as for Chameleon), while other

products price them as separate options (such as for IBM's OS/2 client). Sorting through all

the various options will take time.

BIO:  David Strom was the founding editor-in-chief of Network Computing magazine and

now runs his own consulting firm in Port Washington, NY. He can be reached via the

Internet at 3193660@mcimail.com. 

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David Strom David Strom Port Washington, NY 11050 USA US TEL: 1 (516) 944-3407