Setting up a LAN connection to the Internet using IPRoute and ISPA

This webpage contains instructions on how you can configure Windows 95 to connect to the Internet, using IPRoute/ISPA as a software router. For lots of information on IPRoute and ISPA, and some background on sharing an Internet connections (modem, ISDN etc.) with multiple computers, click here.

These Windows95 setup instructions were to a large extend 'borrowed' from the WinGate instructions on Or, I should rather say that I used the "look and feel" of that page. That's because the actual configuration itself is easier, compared to WinGate.

Using special software, you can configure a DOS machine (with a modem or ISDN card) as a gateway machine that allows Windows 95, OS/2 Warp machines, Linux machines etc. that are connected by network adapters and cables to access the Internet through the same connection. You MUST have network cards in order to make this work.

What You Need to Get Started:

There are two main parts to setting up this connection: The machine that has the modem/ISDN card and the working connection to your Internet Service Provider will be called the Gateway machine. The IPRoute software runs ONLY on the Gateway machine. After setting up the Gateway machine, you must configure the TCP/IP stacks on the workstations to the Gateway machine as a gateway (the Internet applications on the workstations do not have to be configured to use proxies). This document addresses both issues.

Part A: Configuring the Gateway Machine

Step 1: Install the Network Adapter in the Gateway Machine

Configure the network adapter's settings: the IRQ (interrupt), DMA and I/O port. For older cards you may have to rearrange some jumpers on the card itself. The newer ones (even the cheap NE2000 clones) come with a DOS configuration program which allows you to change the settings through software. In most cases the default settings should work. Sometimes the DOS configuration programs warns if the adapter's settings are conflicting with other hardware.

Power down your machine and install the network adapter card according to the instructions provided by the manufacturer.

You have to obtain a so-called DOS "packet driver" for the adapter. In most cases, the network card comes with a floppy disk containing such a driver. If not, you can download a set of drivers from several places, including this site.

Step 2: Install and Configure ISPA on the Gateway Machine

If you don't have an ISDN plugin card (ISA/PCI), but an ISDN modem or a normal modem instead, you don't need ISPA and then you can skip this step. ISPA is a driver written by Herbert Hanewinkel, which lets your ISDN plugin card appear as a network card. For examples how to make a configuration file for this driver, see this page. If you don't have a copy of ISPA, you can download it from his site.

Step 3: install and Configure IPRoute on the Gateway Machine

IPRoute is an application written by Dave Mischler. If you don't have a copy of IPRoute, you can download it from his site.

Because of the way IPRoute works, you'll need to assign some special (known as "private" or "dummy") IP addresses to each of the machines on your LAN, including the Gateway machine.

IP Address

Type in as the IP address. This is a private address that won't exist anywhere on the Internet, so you can let the Gateway machine use it for the internal LAN only. The "dummy" Class C subnet 192.168.0.x is to be used for all machines on your subnet. See also RFC1918.

Next, use as the subnet mask.

Part B: Configuring the Windows95 Workstation(s)

Step 1: Install the Network Adapter in the Workstation(s)

Power down each Workstation and install the network adapter card according to the instructions provided by the manufacturer. Connect your network cables and make sure that they are properly terminated. You cannot simply connect one end of an ethernet cable to the Gatway machine, and the other to the Workstation. If you use Ethernet (10Base2, coax cable) you must use "T-connectors" with terminators on one end of the T-connector at both "end" machines in the string of computers. If you have 10BaseT, TokenRing, 100BaseX or whatever, you need a "hub". Do not install any software drivers for the network adapter - there is a good chance that Windows 95 will auto-configure the adapter when you turn on the machine.

Restart Windows 95 and watch to see if it auto-configures (you'll see a message telling you what it is doing and it will reboot). If it does not auto-configure your network adapter, press the Start button, select Settings..., then Control Panel. Double-click the Add New Hardware icon. Follow the prompts and Windows 95 will install your adapter and reboot.

Step 2: Install TCP/IP on the Workstation(s)

Press the Start button, select Settings..., then Control Panel. Double-click the Network icon. You'll see a dialog box like this. To install TCP/IP, hit the Add... button, double-click Protocol, then select Microsoft, then TCP/IP, and hit OK.

Step 4: Configure TCP/IP on the Workstation(s)

As was stated before, you'll need to assign some private IP addresses to each of the machines on your LAN. Since you've already given a private IP address to the Gateway machine (, you'll need to provide unique IP addresses in the same subnet to the Workstations on the LAN. If you don't know what that means, don't worry. Just number all your LAN worksations consecutively, starting from, then and so on. For example, since you used for the Gateway machine, use for the first Workstation, for the second, etc. Make sure you choose a different private IP address for each machine, and remember which number you chose.

On each of the Workstations, press the Start button, select Settings..., then Control Panel. Double-click the Network icon. You'll see a dialog box like this. Select the TCP/IP properties. Press the Properties... button. You should get the TCP/IP Properties box.

There are six sections in this dialog box. We'll deal with them in order. In each case, you can click on the section title to get a picture of the dialog box with the correct options selected.

IP Address

(Please note: ignore the in the picture, it must be,, etc.!)

Select the Specify an IP address option. Then type in the unique private IP address you chose for this machine. It must not be the same as any other machine on the LAN, including the gateway machine. If you accidently do use the same address as some other machine, Windows95 will popup a message saying that somebody else is using the same address and that you will have to do something about that. Next, fill in the Subnet Mask text area with

WINS Configuration

I don't think ISPs support this so select the Disable WINS Resolution option for now.


Select the New gateway option. Then type in the private IP address you use for the Gateway machine, Click on Add (no, if you click on OK it won't be added!)


By default, the Client for Microsoft Networks option is checked. Leave it alone.


No changes needed are from the default.

DNS Configuration

Select the Enable DNS option. Enter any name you want the machine to be known by (internally - the Internet cannot see these machines) in the Host box. For instance, one of my machines is called kwak and has IP address You can leave the Domain box blank if you want, or you could use the domain name of your ISP.

You may want to set up a HOSTS file if you want to reach the other machines on your LAN using their name and not their number (192.168.0.x). This is explained in the next step.

This is an important step. Without a DNS specified, the Workstations will not be able to use Internet names (like but only Internet numbers (like In the DNS Server Search Order field, enter the IP number(s) of the Domain Name Servers (DNS) used by your ISP. If you don't know what these are, call their helpdesk, they should be able to give you this essential information. Click on Add (no, if you click on OK it won't be added!). Normally, I don't bother with Domain Suffix Search Order.

Step 5: Set up a HOSTS file on the Workstation(s)

A HOSTS file acts as a local database that tells your computer where to go when it's looking for a certain address, kind of like a "mini-domain name server." Use NOTEPAD, EDIT or whatever to create a new text file. You can add entries in this file for the IP addresses and the names you gave to your Workstations, separated by at least one space. You can also add an entry for the Gateway machine if you want. Here's an example of the structure of this file: gateway kwik kwek kwak
Make sure you press ENTER at the end of the last line of text, otherwise Windows 95 may have trouble recognizing it. Save your file in the \WINDOWS directory with the filename HOSTS with NO file extension (for those who care, the HOSTS file entries do not replace or interact with NetBIOS names in any way). Notepad is a braindead program, so in order to save a file name with no extension in Notepad, you have to surround the name in quotes, and add a dot to the end. Crazy. You might want to use good old EDIT from DOS instead.

Step 6: Test the LAN's TCP/IP Connection

Fire up all the machines (including the Gateway machine). Do not dial your Internet Service Provider yet; you still have a couple more things to set up. However, now is a good time to make sure that everything is working smoothly up to this point.

From the Windows 95 command prompt, type

ping gateway

from each of your Workstations. If you get a response back, then the TCP/IP connection between the machines is working. If you get a Request timed out message, or a Bad IP Address response, check your physical connection between the machines, then go back and check all previous steps.

Once the Gateway machine replies to pings from each of the Workstations, it is time to test your DNS setup.

Fire up ISPA and IPRoute by executing the batch file. Next, go to a Workstation, and type

You should get a message back similar to the following:
Pinging [] with 32 bytes of data
40 bytes from ( icmp_seq=0. time=236. ms
40 bytes from ( icmp_seq=1. time=306. ms
40 bytes from ( icmp_seq=2. time=284. ms
40 bytes from ( icmp_seq=3. time=277. ms
This means that your Workstation was able to look up the name and that the host is reachable. If you don't get the first line, there is something wrong with your DNS settings, and you should check the previous steps.

Step 7: Configure the Workstations' Internet Software

In contrast with WinGate, you will not have to tell all your Internet software to use proxy servers. Most programs will run out of the box with IPRoute. However, you will of course still need to follow your ISPs guidelines to access their newsserver, mailserver, webserver, FTP server, what have you, but this will be exactly the same as if the Workstation was connected to the ISP using a modem/ISDN card.

Some ISPs offer a cached proxy server for the WWW. You can configure your browser to take advantage of that. (The proxy server runs on an machine of your ISP, not on yours).,


Go to Options, Session Options, and make sure that Use PASV Transfer Mode is NOT checked. Choose Save as Default, and exit the Options dialog.

WARNING: I have no idea if the following is requiring. Just try without it, and if WS_FTP doesn't work, enable it and see if it solves the problem: for each FTP session name you create, select Advanced and select the User with no logon option.

Other client apps

There is a list of apps on my other webpages.

Getting Connected

Everything should be ready to go! Fire up the Workstations and try using some Internet apps. The Gateway machine should dial out since there is some traffic directed to the Internet. If the Internet apps aren't working correctly, but you're sure they can access the Gateway (you can ping the gateway), double check the Gateway and Subnet Mask settings in TCP/IP configuration of Windows95.

Final Notes

If you have support questions concerning IPRoute, you should register the software and direct your questions to Dave Mischler. For more information about features and/or options with IPRoute, please refer to the IPRoute documentation.