To communicate on a network a machine must have a valid IP address and some configuration settings. Most modern computers and devices today use DHCP (Dynamic Host Configuration Protocol) to get their IP address automatically from a router on the local network. mTCP includes a DHCP client that allows your PC running DOS to get an IP address using DHCP.

The mTCP DHCP client is very simple - its only job is to talk to a DHCP server and get an IP address for your machine. It has been tested with a wide variety of DHCP servers and routers.

Below is a screen shot of DHCP running:

In the screen shot we can see that the machine (a simulated machine using DOSBox) was given an IP address, network mask, gateway address, and a nameserver address in a lease that expires after one day. The nameserver is using Google's public DNS system which is generally very fast and highly reliable. The settings are written to a file so that they can be read and used by other mTCP programs.

Lease times generally range from 30 minutes to several hours. When the lease expires the DHCP server is free to give the address to another machine that needs an IP address. If an mTCP program detects that the lease is soon to expire it will warn you so that you can run DHCP again to renew the lease. Having two machines using the same IP address is a bad thing, so when in doubt, run the DHCP client before running an mTCP program to ensure the assigned IP address is fresh.

The mTCP DHCP program requires that some setup be done before you can use it. Please see the mTCP documentation for how to do that setup.

Static configuration

If you do not have a router or DHCP server on your network you can always configure the IP address and network settings by hand. Before DHCP most machines were configured that way but now DHCP is far more common. The mTCP documentation has instructions for performing static configuration too.

Download

DHCP is included with the other mTCP based applications. They can be downloaded from the main mTCP page here.

Created July 2nd, 2015
(C)opyright Michael B. Brutman, mbbrutman at gmail.com