Notes on Ping
-------------

PING.EXE is a DOS ping client.	Ping is the most basic service of all; all
it does is send packets to another machine on the Internet and see if they
come back.  This program didn't come with any documentation (PING.EXE is
the actual program, not a self-extracting archive).  According to text
strings contained in the executable, it supports both class 1 and class 6
packet drivers.

Judging by the way the program behaves, it is a Trumpet TCP application like
Trumpet IRC, where the Trumpet TCP/IP stack is contained in the application
(i.e., you do not need to load NTCPDRV.EXE to use it).  That means that it
uses the following DOS environment variables for configuration:

   IP (your IP address)
   NETMASK (your netmask)
   GATEWAY (your gateway's IP address)
   DNS (your nameserver's IP address)
   MSS (largest packet you will agree to receive)
   RWIN (size of buffer for incoming packets)

If IP or MYIP is not set, Ping will attempt to use BOOTP to configure
itself.  MSS and RWIN should, however, be set to 512 in any case for
compatibility with Frank Molzahn's SLIP drivers.

To use the program, just give the name of a site or an IP address of one:

   ping www.agate.net
   ping 199.191.1.2

<esc> exits the program.

Ping is useful for testing your packet driver.  For testing purposes you can
set its environment variables on the command line, then run it.  Later, of
course, you will want to automate the setting of those variables.

You can also use Ping to test whether you have BOOTP working.  To make it
use BOOTP, unset the IP and MYIP variables like so:

   set ip=
   set myip=

If you get "ICMP error", then you don't have a proper Internet connection. 
If it can't find the site you're trying to ping (and it's a valid site name)
and uses its default address, you don't have name service.