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Networking FreeDOS - Loading the TCP/IP

Kernel (Stack)


Modern operating systems have their own TCP/IP kernel already built-in: Microsoft systems come with "Winsock" since Windows 95. In GNU/Linux the TCP/IP stack is part of the Linux kernel. DOS however comes without kernel. So after we had installed our packet driver, we have to give the TCP/IP kernel a thought.

How it works

The TCP/IP kernel is also called "stack" or "protocol stack", because it consists of two layers: IP and TCP. IP runs on top of the hardware driver and TCP on top of IP, providing an interface to network applications. For DOS different types of TCP/IP kernels are available. (Picture of TCP/IP kernel) As we see in the figure above, they can either work as external programs or they are already built into the applications. * An external TCP/IP kernel is typically started by AUTOEXEC.BAT or by a batch-file. It stays memory resident, so it can answer ping requests for instance. * Other network applications come with TCP/IP kernel functions already built-in and do not need an external TSR kernel. An application with built-in TCP kernel has the advantage that it doesn't need another driver which consumes precious DOS memory. On the other hand TCP/IP functions are limited to those of the network application and are only provided as long as it runs.

Configuration needed

Every TCP/IP kernel must be configured with general information about the network, as IP address, netmask, nameservers and gateway, or it must be told to get this information via a BOOTP or DHCP server.


Examples for external TCP/IP kernels for DOS are * the free Trumpet TCP kernel NTCPDRV.EXE, * the TCP/IP kernel of Novell NetWare TCPIP.EXE, * Microsoft MS client's TCPTSR.EXE and * FTP Software Inc.'s ETHDRV.EXE. Examples for TCP/IP kernels built into DOS applications are * WatTCP, which is f.i. already built-in the graphical web browser "Arachne", * the mTCP kernel, written in 2009, * the KA9Q kernel which is part of that program, * the NCSA Telnet kernel which is built into the applications included in this suite, * the CUTCP kernel and * the University of Minnesota stack, which is part of "MINUET". More than half of the DOS networking applications available use the WatTCP kernel says Jeffrey L. Hayes from the retrocomputing website (*01) (see: internet/readme.txt (*02)). So most of us will not have to install a TCP/IP kernel at all. Instead we only have to care about the WATTCP.CFG configuration file for those networking applications. The next chapter takes a closer look at WatTCP and its successor Watt-32. Then we will examine NTCPDRV which is the only free external TCP/IP kernel available. Afterwards we briefly look at other external TCP/IP kernels. * [WatTCP/Watt-32] * [TCPDRV]/[NTCPDRV] * [mTCP] * [Others] (*01) OK (*02) OK ------------------------------------------------------------------------------ Copyright (C) 2007 Ulrich Hansen, Mainz (Germany), modified 2010 and 2020 by W.Spiegl. For more information see here. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation. A copy of the license is included in the section entitled "GNU Free Documentation License 1.2".