Setup TCP/IP Routing

by Johannes Helmig [Published on 28 June 1998 / Last Updated on 28 June 1998]

I am using the following network to explain the setup requirements of Routing (assuming that you have knowledge of TCP/IP setup and on setting up systems with MULTIPLE network adapters):

Some of these systems are/can beWindows95/98, some are/MUST be NT4 / 2000.

System #1:
This system (can be Windows95/98 or NT4) has only 1 Network card and is configured (example is using NT4) :

This system knows about all systems on its own network cable (192.168.1.x) and will use the Gateway/Router (which is System#2) for communications with any other system.

This is a Windows NT4 system configure with 2 Network cards:
Network configuration, tab : Adapters :
- 1: a 3COM Etherlink III (3C609)
- 2: a Novell NE2000 Adapter

The first Network card communicates with System#1:
Network configuration, tab : Protocols
- Properties of TCP/IP
- selected Adapter : Novell NE2000
- selected radio button : Specify an IP Address
- IP-address:, Subnet Mask:
, no gateway address defined :

the second Network card communicates with System#3:
Network configuration, tab : Protocols
- Properties of TCP/IP
- selected Adapter : 3Com Etherlink III (3C509)
- selected radio button : Specify an IP Address
- IP-address:, Subnet Mask:
, no gateway address defined :

In addition, NT4 TCP/IP protocol must be configured to "route":

System#2 can communicate directly with System#1 and System#3, but NOT with System#4 (because it does NOT know about a network 192.168.3.x and how to reach it).

We need to help System#2 by giving some information, on how to get to System#4, by either defining System#3 as a Gateway or by manually manipulating the TCP/IP routing tables using the command-line utility ROUTE.
ROUTE.EXE is part of Windows95 and Windows NT4 and is documented in the Resource Kit:

You can get the same information by using a Command-Prompt window and
typing : "route /?" ( text-file of the output from an NT4 system )

In our example, we would enter on system#2:
this informs System#2, that all communications for TCP/IP addresses 192.168.3.x(the '0' in the route-command translates to 'each system with an address 192.168.3.x', which in our example includes System#4) has to go via ( which is System#3).

The rest of the Network is configured similar to Systems#1 and #2.

If you like more info on the ROUTE-command, please look at the following article in the Microsoft Knowledge Base:

Test your setup using PING:
Example: from System#1 :

- command : "ping" getting a reply
- command : "ping" getting a reply

System#1 can communicate with System#2 and #3 in this test.

Example: from System#3

- command : "ping" getting a reply
- command : "ping" : message "Destination host unreachable"

System#3 can communicate with System #2, but NOT with System#1.
In such cases, check on ALL system the IP-addresses, Gateway-addresses and that IP-forwarding is enabled.

And don't forget: IT MUST WORK IN BOTH DIRECTIONS, otherwise the system receiving the PING-test-signal does NOT know on which route to send the echo back !

Browsing a system, which is accessed via a Router

Workgroups have limitations, and one of them is:
Systems on different network cables cannot be in the same workgroup !
To access a system via a router, you need to use the "Find"-command in the Windows
Start-bar and search for a "Computer" :

To avoid to get an Error-message : "The network name cannot be found" :

you need to create/update the file "LMHOSTS":

On Windows95/98, a sample-version called LMHOSTS.SAM is installed with TCP/IP in your Windows-directory. Rename/copy it to LMHOSTS and enter the IP-address with the computername. On Windows NT4/2000/XP, the files LMHOSTS and/or LMHOSTS.SAM
are located in "C:\<Windows-directory>\system32\drivers\etc".

Then you can "find" this system:

Now the big question: Can I use Windows95 as a Router ?

Officially: NO.
Microsoft has reserved the functionality to route for Windows NT.

Unofficially: YES, but with limits
I have not yet tested this myself, but have seen in the Newsgroups several postings, that it is possible

Want windows 95 to act as a router!
( )
using Windows95 as a TCP/IP Router between ONE Ethernet-cable and a Dialup Networking connection with a STATIC IP-address :

Apparently, you need the Dialup-Networking Upgrade 1.2, which includes a TCP/IP upgrade,
and then need to define in your Windows95 Registry:
key : [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP]
create a new sub-key "EnableRouting" , value (as StringValue): "1" :

I repeat: I have NOT tested this myself on Windows95 , and can therefor NOT ANSWER
any question on this topic.
I have tested this on Windows98SE, where it is working !

See Also

The Author — Johannes Helmig

Dr.Johannes Helmig is working as Director, Technical Knowledge Management in the Belgium office of Gerber Technology where he is involved in Customer Service and internal training, with special interest in Networking.


Featured Links