# -*- mode: text; tab-stop-list: (2 4 6 8 10); indent-tabs-mode: t -*- # $Id: README,v 1.2 2000/03/26 21:27:10 rcaputo Exp $
TABLE OF CONTENTS
What poing Is
Requirements
Compatibility
Getting Up and Running
Troubleshooting
Author Contact and Copyright
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WHAT POING IS
Poing is a multi-host ping program with a "strip chart" style display. It not only lets you see hosts' current status, but it also shows at a glance how they've been responding over time.
REQUIREMENTS
Poing requires a terminal that supports ANSI or VT-100 cursor positioning and color sequences. It doesn't have to honor the color sequences with actual color, but it should at least fail to display them. The color's real sweet, though.
Your shell should set environment variables that indicates the terminal's width and height. Known variables are: COLS, COLUMNS, ROWS and LINES. Poing will assume an 80x25 terminal if the environment variables aren't supplied.
Poing requires Perl, version 5.004_04 or newer, and the following Perl modules, which are available from the CPAN:
POE
Time::HiRes
You can download and install the modules the hardcore tarball way. Visit http://www.cpan.org/ to find a close CPAN mirror.
They may be installed using the CPAN shell:
% perl -MCPAN -e shell
If this is your first time using the CPAN shell, you'll be asked some questions about your system and the archive you'd like to use. The CPAN shell will present you with a prompt once these first-time formalities are taken care of.
Once at the "cpan>" prompt, you can type:
cpan> install POE
cpan> install Time::HiRes
Each command should build, test, and (if the tests pass) install a module. When they're done:
cpan> quit
To return to your shell prompt.
COMPATIBILITY
Poing will run wherever POE does, which is a decent subset of supported Perl platforms.
GETTING UP AND RUNNING
Here's the quick walk-through for setting up and running poing.
- Inspect the program's source for trojans or other nastiness. Since the author runs poing daily, he's taken great pains to make sure it contains only harmless code. Prudent system administrators understand that this is no guarantee that things will work on their systems.
- Note the default parameters at the beginning of the program. Note the default host list at the end of the program.
- If the defaults are not to your liking, then create ~/.poingrc to
override them. Here is an explanation of the available .poingrc
- directives
How to specify hosts to ping.
By numeric address. Poing will try to resolve a host name from
the address. The host name will be displayed if one is found,
otherwise the numeric address will show.
host <numeric address>
For example:
host 127.0.0.1
By host name. Poing will display the host name and ping the
address, if one can be resolved. Some host names may point to
several addresses, so this form of the host directive is sloppy
and not recommended.
host <host name>
For example:
host localhost
By numeric address and symbolic name. This is the recommended
method, since it bypasses the start-up delay and vagarities of
the DNS.
host <numeric address> <symbolic name>
For example:
host 127.0.0.1 localhost
How to set the ping timeout.
To specify the ping timeout in seconds (fractions are okay):
ping_timeout <seconds>
Some examples:
ping_timeout 2 # This got the author in trouble
ping_timeout 3.14 # A nice round number
ping_timeout 10 # Relatively friendly
How to tell when hosts die.
Poing does some things when a host becomes unresponsive. It
beeps to tell you something's wrong, and it dims the strip chart
for that host.
Poing determines host unresponsiveness tracking how long a host
hasn't responded to echo requests. The amount of time a host
can be quiet before it's considered dead is specified with the
detect_host_death directive:
detect_host_death <seconds>
For example:
detect_host_death 30 # Quiet for half a minute == dead
Packets are lost all the time; especially low-priority packets
like ICMP ECHO-REQUEST. Poing will interpret this normal
transient packet loss as host death if detect_host_death is set
too low.
The author's experimentation has determined that the greater of
three times the ping_timeout or 15 seconds is a good starting
value for detect_host_death.
How to tell when hosts come back from the dead.
The detect_host_life directive works like detect_host_death, but
it detects when dead hosts are back. Generally, it should be
set to match the detect_host_death value.
detect_host_life <seconds>
For example:
detect_host_life 30 # It's been back for half a minute
How to log host deaths and resurrections.
Finally, the log directive will enable poing's logging facility
and tell it the file where it will record host status changes.
The file is tab delimited, with the following fields:
GMT date/time stamp
status message
numeric address
symbolic name
The status message will be one of these four strings:
begin = Poing has started.
cease = Poing has stopped.
up = The host has come back to life.
down = The host has been quiet. Too quiet.
The "begin" and "cease" lines won't include a host address or
name.
4. Run poing:
sudo poing.perl
Or run it with root privileges some other way.
TROUBLESHOOTING
Stuff happens. Here's how to work through it and come out smelling like a rose. Please let the author know if you encounter problems not listed here.
You see the error "Can't locate [whatever] in @INC [yatta-yatta]".
Module [whatever] is not installed. This can happen if it didn't pass tests. Try reinstalling the [whatever] module, and watch its progress closely.
icmp ping requires root privilege at [yatta-yatta] line [yatta-yatta].
Poing transmits ICMP ECHO packets, which require a raw socket. Only root can open a raw socket on your operating system. This is your cue to carefully examing poing.perl and decide whether you want it to run as root.
Poing only opens one file, and it's opened read-only. It doesn't do anything else to your filesystem. Don't take my word for it, though; examine the program yourself for the utmost in warm-fuzzy security.
Poing things my terminal width is 80 and/or its height is 25, but they really aren't.
Poing looks for COLS or COLUMNS to determine your terminal width; and LINES or ROWS to determine its height. Your shell may be setting one pair of these variables, but they haven't been exported to the environment.
Check your shell's manpage for the proper way to export the variables it uses, so that Perl can see them and poing can use them.
AUTHOR CONTACT AND COPYRIGHT
Poing is Copyright 2000 by Rocco Caputo. All rights are reserved. Poing is free software. You may use, modify and/or distribute it under the same terms as Perl itself.
The author may be reached as "Rocco Caputo" <troc+poing@netrus.net>.
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Thanks for reading!