My Little LAN

Content by John Summerfield, © 1997 (original archived HERE, old URL).


Setting up a home LAN

Questions I often see in the Internet news groups go along the lines:

    How do I connect both my machines computers to the Internet 
    Can I send mail across my LAN 
    How do I use the modem attached to my other computer to send faxes
Within limits, I've done all these things and more on my little LAN.

Introduction
My networking skills have improved over time and some of what I see here I now know isn't necessary: in particular, OS/2 Warp Connect and Warp 4 do not need any TCP/IP routing to find hosts on the same subnet. However, to fix it without a complete rewrite is to claim my network was perfect from the beginning... 

However, the LAN as described here worked perfectly well so the errors are not serious. 

My LAN has evolved over time and each step forward has added improved functionality. The first notable change was when I added a second OS/2 computer. The most significant point here is that I had been running a Web Server on OS/2 for a while and now I configured it as a proxy and was able to access the Internet from two computers simultaneous. There were some minor limitations, however, as only the computer with the Internet connection had direct access to telnet, mail and ftp. To be sure, the second computer could use ftp, but only using a web browser configured to use the first as proxy. 

To be accurate. Maximus was to replace the P100, but for a week or so there were three computers on the LAN. Some time after I wrote this I decided the i486 was altogether too painful running Warp Connect and it would be nice to have a fulltime Linux machine. The i486 computer does this nicely, though to be truthful it only has a light load. 

Some time later the P100 returned so my LAN now has three computers. 

In March 97 I added a SOCKs server and figured out how to configure the DDNS. Now when Cretin goes Internetting, Maximus goes along for the ride. It can now fetch & send mail and has ftp access to the world.

Main topics

My computers
   I have two computers connected with a pair of NICs and length of coax. Their network names are p100 and i486. An Ipex 486dx33 with 8 Mb RAM and two Quantum drives totalling 590 Mb of disk space. This machine has Lotus Smartsuite for Windows network-installed on OS/2 Blue Warp Connect. It also drives my HP Laserjet IID. 
   OS/2 Warp Connect does not perform well on this machine: it badly needs more RAM. 
An Optima P100 with 16 Mb RAM and about 2 Gb if disk space. It normally runs OS/2 Blue Warp Connect. It has a node install of Lotus Smartsuite, and owns the family CD & modem. 
The p100 sometimes runs Linux.

What I can do with these computers
When running Connect on both machines

    From the i486 I can dial into the Internet and use the Internet software. 
    From the i486 I can send faxes. 
    From the P100 I can print on the laser printer using Peer services. 
    From the P100 I can print on the laser printer using TCP/IP. 
    From the i486 I have some Internet access while the p100 is connected. 
    From either use ftp to transfer files. 
    From either send mail to the other using Ultimedia Mail Lite. 
    Another way has become available since I set this up
When running Linux on the p100 and Connect on the i486
    From the P100 I can print on the laser printer using TCP/IP. 
    From either use ftp to transfer files. 
    From either use telnet to connect to the other 
    Given that the Linux CD includes 
      httpd, a WWW server 
      INN, the news server used by my Internet Service Provider 
      A recent sendmail 
      and that other necessary software is readily available (my ISP uses Linux), I can set up a full range of internet services on my LAN.
    In addition, Samba, a NetBIOS client/server package, is one of the many packages on my CD, so I can set up file & print sharing facilties in Linux to share assets controlled my Peer & vice versa. 
My setup
   Both computers have OS/2 Peer installed. This allows me to share drives and peripherals. For example, drive I on both machines is the CD. I can define a printer on the i486 attached to a port on the p100 and use it as if it were a local printer. I can and have defined a network printer on the p100. This is used for printing, of course, but the queue is maintained by the i486. 

   Both computer have TCP/IP 3.0 installed from the OS/2 Warp Connect CD. Had I installed from the bonus pack CD, I'd have fewer TCP/IP facilities and no TCP/IP connectivity for the LAN. 

Setting up the LAN
Do read all available documentation before starting, particularly README files. 

   I purchased two ACCTON EN1666 Network Interface Cards. These are fairly new Plug & Play NICs that are not supported by Warp Connect as distributed. However, the necessary drivers and setup program come on a pair of floppy disks. I ordered the cards "and all necessary bits" by mail order, and had them on hand before I had a computer to install Connect on. 

These cards can be connected by coaxial cable or by twisted-pair. 

Installing the software was straightforward. I had read somewhere of problems installing the LAN software: I think involving the Novell requester. The circumvention was to install one requester at a time.

MPTS
When installing the network software one also installs Multi Protocol Transport Services, MPTS, also MPTN though don't recall what the N stands for: so far as I'm concerned any difference is insignificant. 

MPTS provides the LAN support. The only point that presents any challenge is configuring the NICs. You must specify the appropriate hardware driver: in my case I had to choose to install a third party driver the for the p100. When installing on the i486, the driver was on the boot disk and appeared in the list with all the others. 

I have installed these protocols:

NETBIOS Must have this or NETBIOS over TCP/IP for OS/2 peer
TCP/IP Required for TCP/IP applications
NETBIOS over TCP/IP This can be configured to talk to SAMBA on a Linux (or Unix or OS/2) machine, I've also read that this is required to share resources from Windows NT. 

According to MPTS there are two kinds of adaptors: physical ones that you can touch and logical ones that it imagines. It won't allow two NETBIOS protocols on the same adaptor, so I've configured NETBIOS over TCP/IP on logical adaptor 1. 

Don't forget to configure TCP/IP sockets access & NETBIOS sockets access. 

Installing Peer
To be safe, I installed Peer first and got that up on the P100 before installing other network software. 

When it came to installing on the i486 I created a pair of network install diskettes: there's a function for that in the Warp Connect Remote Install folder within the OS/2 Warp Connect Install/Remove folder. A nice touch, I thought, was the question "Do you want your ACCTON drivers on the install disks?" 

Before beginning, I had to make space on the 486 system. To give me a LAN connection, I jiggered the grpware.ini file in the C:\GRPWARE\clients directory and the install disk to give me access to more disks. Here's my current grpware.ini file: compare it with yours to see what's changed. 

;SRVIFS INI file for GRPWARE - HCNY08WO
Name = HCNY08WO
GroupName = NO
Adapter = 0
MaxClients = 1
MaxFiles = 9999
ClientWorkers = 6
Path = i:\
Alias = ReadOnly,Single,CDROM,i:\
Alias = ReadWrite,Single,STATUS,C:\GRPWARE\CLIENTS\LADCLT
Alias = ReadWrite,Single,DRIVED,d:\
Alias = ReadWrite,Single,DRIVEC,C:\

I do not pretend to understand this file, but the changes I needed seemed fairly obvious. I have since read that if you want to install on more than one machine at the same time, you only need to change maxclients to a larger number, but do beware of thrashing on the CD.This allowed me to move files around with ZIP & XCOPY so as to make some room on the i486. 

When I went to install Connect on the i486, the installer noticed that Warp was already installed on the system and gave me the option of simply installing the networking software. This I did, and that system works fine, though I have subsequently reinstalled Connect on this system and use MSHELL rather than PMSHELL as the user interface. 

Installing Peer is pretty simple and there are few significant choices to make. And where numbers are called for, accept the defaults. 

I've settled on the name i486 and p100 for the computers: the same names as their TCP/IP names, though this isn't necessary. Indeed their Peer domain name is different from their TCP/IP name, and in some networks this may be appropriate as one of the tools to control sharing. 



Printing with Peer
Standard OS/2 printing works for those machine where the printer is directly attached to the computer in question. As that's not a Peer function, lets go onto other things. 

Creating a printer object
There are two main ways of creating a printer object with Peer. One is to share a printer port and each user defines a standard printer object using it. The other is to create a Network printer. 

Sharing a Port

    In the Sharing and Connecting object of the computer with the printer define its port as an object to be shared. For the purpose of discussion, I'll assume lpt1 on i486. 
    In the Sharing and Connecting object of the other computers define lpt on i486 as an object to use. 
    Define a printer object attached to lpt1. 
I tested this with the DIR command from an OS/2 Window with satisfactory results. However, I do not know how sharing conflicts are resolved. 

Whilst I didn't actually try it, I can see no reason this shouldn't work from a Windows or DOS program. 

If you share a printer this way, your settings must be appropriate to the actual device. Some coordination with others is necessary, for example, stationery, sheetfeeder etc. 

Network Printer
Before you can create a network printer, you must have defined the target printer object on the host machine. After that, creating a network printer is simply matter of dragging a Network Printer from the Templates folder and completing the form. This creates a printer object whose settings you may wish to review. It will undoubtedly work best with settings compatible with those on the host with the printer. 

The Sharing and Connecting object in the OS/2 Peer folder is the place to define objects to be shared with others and object belonging to others you wish to share. 



Presentation Manager Applications
These function as expected. The network printer and local printer objects are just another printer. 

OS/2 (non-PM), Windows & DOS programs
From Lotus Smartsuite I print to lpt1.os2 using the Laserjet Series II driver. I have a network printer defined as attached to lpt1: as far as I can tell the sole reason for this connexion is to pick up prints from DOS, Windows and non-PM OS/2 applications. 

Sending Faxes
Sending faxes is simply a special case of printing. The computer with the modem (p100 in my case) needs Faxworks installed. Create a printer object using the Faxworks driver. You can use either of the techniques above to create a printer object on the client machines. I've installed the IBM Proprinter XL24 driver (4208)

The fax form-filling is done on the machine with the modem. While this might be fine at home or in a small office, larger offices would be better with the Pro version which includes more device support, PCL emulation and directly supports LANs.

Configuring MPTS
The program object for configuring MPTS has varying names: On Warp 4 it's called Adapters and Protocol Services. Whatever it's called, it runs a program called "MPTS."

For the porpose of discussion, we'll assume we're installing new equipment.

    On starting MPTS you are presented with an array of pushbuttons one of which is called Configure. Click this one. 
    In the Adaptors & Protocols section, LAN Adaptors & protocols is selected. Click Configure.
    You're now looking at a window containing three separate areas. Highlight the driver appropriate to your NIC and press Add or press Other Adaptors if you need to load one from floppy or some other source.
    Choose the protocols you need. These are probably
      NetBIOS for standard file & print sharing
      TCP/IP if you want to run Internet apps, either on the LAN or with the Internet.
      NetBIOS Over TCP/IP if you want to share printers & files with some other machines such as Linux running Samba.
      This is also good for sharing things across the Internet.
      Some people may want one or both Netware protocols.
      Few people will want IEEE 802.2
    Make sure that IBM OS/2 NETBIOS and IBM OS/2 NETBIOS OVER TCP/IP have different logical adaptor numbers. If necessary, highlight one and press the Change Number pushbutton.
    If you've installed NETBIOS over TCP/IP
      Highlight NETBIOS over TCP/IP in theCurrent Configuration window.
      Press the Edit pushbutton.
      Choose Names List and press Configure
      Add entries for any machines you wish to contact using this protocol. you need the NetBIOS name (or prefix) and the corresponding internet address: this can be local to your LAN or across the world & bridged by a TCP/IP network such as the Internet.
      Click OK.
      Choose Broadcast List and press Configure
      Add names or IP addresses for the machines you wish to connect to. These can be local to your LAN or anywhere else accessible to the TCP/IP protocol.
      Click OK
    Repeat the above steps as needed for any more NICs your wish to add/configure. 
    Click OK to close the LAPS Configuration window
    If it's not greyed out and you've installed TCP/IP, select TCP/IP Configuration and click Configure. This is greyed out in my versions, but as I recall there are no forms to fill in. 
    If you've installed NETBIOS select NETBIOS Configuration and click Configure. As I recall there are no forms to fill in in the original Warp Connect version. Others, simply click OK
    Click Close, Exit etc as needed to finish MPTS processing and update config,sys.
    On Warp Connect, open the OS/2 Peer folder and run Installation. Don't actually change anything. The program apparently inspects the MPTS configuration, presumably to see what protocols it can use. 

    I don't know just what circumstances require this step: changing the protocols around seems to while simply changing the rfcnames doesn't require it. However, it only takes a couple of minutes and may well make the difference between a happy computer and a sad one. 

    I imagine this step is also necessary on Warp 4 and something like it on Warp Server. 

A bug
Some versions of the MPTS configuration program don't allow one to add names in the NETBIOS over TCP/IP Names list. Here are the files: 
\ibmcom\rfcnames.lst
"bbs" 194.184.50.6 "chess" chess "DEL" 194.184.50.11 "step" 194.184.50.12
\ibmcom\rfcbcst.lst
194.184.50.11 194.184.50.12 194.184.50.6 chess
As you can see, any text editor will do to maintain them. 

If you changed these files, you can run the program rfcaddr and use the changes without rebooting.

People have written and asked how to configure Samba. Here's my smb.conf you' see many rlics of my groping in the dark as I tried to get it working. So here it is, without explanation. 



Installing TCP/IP
Actually, installing TCP/IP is quite simple. Getting it configured isn't. The problems lie in the documentation. IBM tells users how to complete fields, but not how to decide what to put there or how to make decisions. Suggestions about consulting with you LAN administrator are not helpful if you ARE the administrator. Third party documentation, notably the Network Administrator's Guide, O'Reilly & Assoc, contain lots of useful info. However, they are directed to Unix & Linux users, and take no account of IBM's TCP/IP Configuration Notebook, driven by the TCPCFG command. TCPCFG retrieves information from and stores it in these files that I've identified:
    config.sys 
    %etc%\sendmail.cf 
    %etc%\sendmail.uml 
    %etc%\tcpos2.ini 
    %etc%\trusers 
    %etc%\hosts 
    %etc%\resolv2 
    %etc%\inetd.lst 
    %etc%\snmp.ini
After almost endless poking around, I have something that works.

TCP/IP configuration for a small LAN
The people who administer Internet standards have reserved some Internet network addresses for use by people who won't be connecting their LAN to the Internet.

There are one Class A address, 16 Class B addresses and 256 Class C addresses. Most of us will be content with a single Class C address which caters for a LAN of up to 255 hosts.

Not that in this context, host refers to a single computer or workstation, whether it be a thumping great IBM S390 with thousands of individual users running under VM/CMS or something more modest such as a PS/2 Model 80 running OS/2 & TCP/IP.

Note also that an individual host may have more than one IP (Internet Protocol) address. In the obvious case, my P100 has one for its NIC which gives it its LAN connexion and another (temporarily) when I dial into my ISP and establish a PPP connexion. I can add additional NICs to get connexions to more LANs or even to gain a second IP address on the one LAN.

Configuration for i486
Here's how I've configured TCP/IP on the i486. You specify all this info in the TCP/IP Configuration Notebook.

    Select Network
      Select Lan Interface 0
        Select Enable Interface 
        Enter the IP address. 192.168.0.3 for i486
      Select loopback interface
        Select Enable Interface 
        Enter the IP address. 127.0.0.1 for all hosts. This is an internet convention. Every host should refer to itself by this address. For one thing, it allows TCP/IP servers & clients to run on the same host without any hardware.
    Select routing. Note that these values may not be necessary, but as my Lan is working...
      Click Add 
      Enter Default as the route type 
      Enter 192.168.0.1 as the router address 
      Enter 1 for the metric 
      Click OK 
      Click Add 
      Enter NET as the route type 
      Enter 192.168.0 as the destination address 
      Enter 192.168.0.1 as the router address 
      Enter 1 for the metric 
      Click OK
    Select hostnames
      Enter your hostname and local domain name. I've used i486 and summerfield respectively. 
      Unless you have a domain nameserver, leave this blank. 
      Unless you know otherwise, leave Lan searchlist blank. 
      Click the arrow to advance to page 2 of the hostnames. 
      Click Add 
      Define an entry for this host. You need to provide its IP address, its host name and any aliases or nicknames you may wish to use. 
      Add entries for every other host on the LAN.
    Select Autostart
      For each TCP/IP application you wish to autostart, select Autostart. You should consider these:
        inetd - can start other services on demand. 
        telnetd - provides the telnet service. Note that telnet on OS/2 is not very secure. 
        ftpd - provides ftp service. Good for occasional file transfer. For file sharing, OS/2 Peer is preferable. 
        lpd - Provides print service. May be useful if you have a Linux box on the LAN or if you want to print over the Internet, although ftp may be a better option there. 
        lprportd - these seems needed too if you're providing a print service. 
        routed - Provides routing functions. I think this is useful if you're providing a gateway service. If you use it, you must have corrective service applied: IC11173 comes to mind. Tony Rall, an IBMer has been putting it out as ic whatever. It's definitely uppercase. In any event, check IBM's Boulder site for a full list of all corrective service
        sendmail - provides the mail transport. sendmail is capable of functioning in both server and client modes. sendmail will receive mail across the LAN and deliver it to Ultimail Lite or other mail program that supports smtp.
    Select General
      If you're using rexec or print service, specify the username of the person authorised to login to your computer?? This name is also used by your lpr client and by emx software. (emx is a software set from the Free Software Foundation. It includes tools useful for porting unix software to OS/2 and if you go searching the Internet for free software, this will become relevant.) 
      Specify your time zone. remember if you're west of Greenwich, specify a negative offset because it's later in Greenwich than where you are. 
      Choose your code page.
    Select Security
      Specify the password to be used by anyone telnetting to your computer. I did say telnet isn't very secure I recall a conflict of name between TCP/IP and Novell's Netware Requester. IBM has a fix - see corrective service above. 
      Define any ftp users. At least here you get to specify different information for different users. 
      Click the arrow to advance to page 2 of security. You probably don't actually want to add any info here.
    Select servers
      I have not established that any of this information is actually used. I use WebExplorer and NewsReader from both machines and occasionally Gopher from the P100. I have p100 in the WWW server field. When I run NR/2 on the i486 I normally start it with the command start nr2 p100. I have told WebExplorer not to load a page on startup and select one from the its Webmap.
    Select printing.
      On the i486 this page has default values.
    Select mail We're now configuring Ultimail.
      Select LAN only. 
      Specify your userid. For a LAN it can be anything - refer to the help. The i486 has this field blank. 
      Leave the mail storage directory alone. 
      Advance to page 2 of the mail configuration. 
      Admire the fields. I've not established that they actually do anything. One can specify equivalent information in the Ultimail Cabinet settings, and I've not taken the time to see whether they both store the information in the same place, or which is used.
    Select sendmail
      You can usually leave the first three fields alone. 
      You may specify your reply domain. According to the documentation, this is the name of the host where your mail awaits your collection. I left it blank for the i486. 
      If you specify an smtp mail gateway, outbound mail is delivered to it. Otherwise, sendmail attempts to deliver mail direct to the recipient. The i486 has this field blank. 
      Page 2 of the sendmail configuration seems to be useful only if you are connected to the Internet and have multiple domains in your LAN: that is, interconnected LANs.
    The snmp page can safely be ignored for small LANs.
Configuration for P100
Here's how I've configured TCP/IP on the P100. 
    Select Network
      Select Lan Interface 0
        Select Enable Interface 
        Enter the IP address. 192.168.0.1 for P100
      Select loopback interface
        Select Enable Interface 
        Enter the IP address. 127.0.0.1
    Ignore routing. 
    Select hostnames
      Enter your hostname and local domain name. I've used p100 and summerfield respectively. 
      I have my ISP's Domanin Name Server here. 
      Lan searchlist is blank. 
      Click the arrow to advance to page 2 of the hostnames. 
      Click Add 
      Define an entry for this host. You need to provide its IP address, its host name and any aliases or nicknames you may wish to use. I have these entries 
        192.168.0.3 i486 
        127.0.0.1 localhost 
        192.168.0.1 p100
      Add entries for every other host on the LAN. I actually have others too, for other reasons, chiefly ftp. 
    Select Autostart 
      For each TCP/IP application you wish to autostart, select Autostart. Refer to my notes on the i486. I have 
        inetd - can start other services on demand. 
        telnetd - provides the telnet service. Note that telnet on OS/2 is not very secure. 
        ftpd - provides ftp service. Good for occasional file transfer. For file sharing, OS/2 Peer is preferable. 
        portmap. I turned this on when I was trying to get tcp/ip printing going. The documentation says it's required for nfs which isn't part of Warp Connect. 
        sendmail - provides the mail transport. sendmail is capable of functioning in both server and client modes. sendmail will receive mail across the LAN and deliver it to Ultimail Lite or other mail program that supports smtp. 
    Select General. See i486 notes 
    Select Security See i486 notes 
    Select servers See i486 notes 
    Select printing. On the p100 I have
      i486 is the report print server 
      lp0 is the remote printer 
      said there are two lpd ports on the i486. This is the minimum acceptable value. 
    Select mail 
      Select LAN + Internet only. 
      I have enabled multi-user mail but have not yet discovered its effect. 
      I have specified summer, my Internet userid. 
      The mail storage directory has its default value. 
      Advance to page 2 of the mail configuration. 
      Admire the fields. I've not established that they actually do anything. One can specify equivalent information in the Ultimail Cabinet settings, and I've not taken the time to see whether they both store the information in the same place, or which is used. However, on the p100 I have specified its own address as the pop server and my internet userid & password. 
    Select sendmail
      You can usually leave the first three fields alone. 
      You may specify your reply domain. According to the documentation, this is the name of the host where your mail awaits your collection. I left it blank for the i486. 
      If you specify an smtp mail gateway, outbound mail is delivered to it. Otherwise, sendmail attempts to deliver mail direct to the recipient. The i486 has this field blank. 
      Page 2 of the sendmail configuration seems to be useful only if you are connected to the Internet and have multiple domains in your LAN: that is, interconnected LANs. 
    The snmp page can safely be ignored for small LANs. 

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