Networking with OS/2 - by Brian L. Juergensmeyer

Hi, everyone. I apologize first for skipping out on the last couple of months. For those that are interested, the hospital that I work for just merged with another hospital of equal size, and merging the routine pool and database proved to be "something of a challenge". However, that is all in the past now, and I'm back and ready to go.

One last thing before we get to this month's article: if anyone out there has any suggestions or requests for me to cover in the monthly networking column, please feel free to let either myself, Chris, or Trevor know. Some of you have already done so, and I've taken some suggestions. Others, while they did make sense and would have been good, were a practical impossibility (the suggestion of a LANAlyzer review comes to mind: I'd dearly love to do just such a review, but a decent LANAlyzer retails for ~$3,000 US. I have access to a LANAlyzer at work but a review based on one product would be kind of lopsided, don't you think?)

Now, on to the show. I had originally intended to write about the formation of TCP and IP packets, and how they interacted, but some of my documentation disappeared. I ended up going straight to the source, and hope to have the relevant RFC's translated into human-speak before next month's deadline.

Instead, an individual saved my life this month by suggesting an article on the use of RAS between OS/2 Warp and Windows NT. RAS (or Remote Access Service) is a method for accessing shared folders on a remote local area network. Basically, it is a method of running NetBIOS over PPP. While it is effective, it is also hideously (and I do mean HIDEOUSLY) slow on anything slower than a true 56k connection. Many of you are familiar with local area networks, and with the process of accessing shared folders over a network. For most, that access is virtually instantaneous. However, most folks are accessing their internal LAN's with a 10 megabit shared Ethernet backbone at minimum. This would give the user a good chunk of that 10 megabit bandwidth to his/herself. When all you have to go over is a 28.8 k modem, however, access does slow down significantly. This is most noticeable when doing a general network browse or when transferring a large amount of data.

However, there are other reasons to use a RAS connection. In addition to being able to access all of your documents as if you were connected locally to the network that contained them, you will actually be a virtual member of that network. I have used RAS at home for precisely that reason. There are two firewalls between my home box and my work box if I attempt to connect to it via my standard, home PPP connection. Developing client-server applications can be very difficult if there are two firewalls between yourself and the server that you are using for development. If I connect to the RAS server directly instead, I can bypass all of the firewalls and can do my network development in peace.

Having said all of that, for those that wish to utilize a RAS server, you must first have the RAS client installed. This is done by either choosing to install the Remote Access Client during the original install of OS/2 Warp, or by doing a "selective install for networking" (found in the "Install/Remove" folder in "Selective Install for Networks"). If you have, by chance, installed a new drive since your original installation of OS/2 (this goes for those of you that have a Zip drive), you will probably have to remark out the driver for your Zip drive to do the selective install of RAS. The Selective Install application requires that you do your selective install from the same drive that you did the original installation of Warp from (IBM, what were we thinking here???).

You may choose to configure a connection to use during the installation of the RAS driver, or you may choose to wait until after you have installed the driver to configure a connection. There will be several items that need to be set up properly for each entry. If you are doing this configuration during installation, these settings will be right in front of you. If you are modifying a current installation, you will need to go to your "System Setup" folder. Inside of your "System Setup" folder there now lives a Remote Access Client icon. Double click on it. After the service starts (which can take a few seconds), right click on the icon representing your PC and select the popup menu that you wish to use.

The first notebook tab is the phone book. You may change the phone number of the remote server that you are dialing here. Next is the answer tab (used by those whose server calls them back). The Dial tab allows you to specify when a popup message appears. You may, if you need to do so, modify the comm ports or the modem you are using for LAN distance remote on the Ports and Modem pages as necessary.

The addresses tab allows you to type in the virtual NIC card address that you will be using. This address MUST be unique across your network. This address is the lowest level of address available to the server. Indeed, the facility that makes a router special is the ability to translate from IP address to NIC address. You will also need to choose which type of networking protocol you are using.

The next page allows you to give the name by which your OS/2 box will be known on the network. The LAPS tab allows you to modify the protocols that you will be using (are you using IPX at work? Here is the place to add it in). Finally, we have timers and security.

The timers are primarily there to ensure that your connection is working the way that it should, and that it hangs up on you when it has been left unused for a certain amount of time. Your defaults should be adequate here. Finally, if you wish to enable security and place password authorization over your computer, the security tab is the way to do it. Note that this only enables security locally, it does not send your NT password to the NT network.

According to the paperwork that I've seen, this setup should then be able to connect to a Microsoft Windows NT RAS Server. However, I've not yet been able to get this to work. I'll report further on it next month, and we'll cover setting up a LAN Distance server and/or another LAN Distance client.

Brian L. Juergensmeyer is a programmer at the VA hospital in Topeka, Kansas. He annoys his IS manager by trying get him to convert from NT/WfW 3.11 to Warp Connect/Warp Server.

Copyright © 1998 - Falcon Networking

ISSN 1203-5696