network-test(1) 						  ifupdown-extra						   network-test(1)

NAME

       network-test - check the network and test if everything is fine

SYNOPSIS

       network-test

DESCRIPTION

       The  network-test  program  will test your system's network configuration using basic tests and providing both information (INFO), warnings
       (WARN) and possible errors (ERR) based on the results of these tests.  It will check and report on:
	      * Status of the network interfaces of the system including: link status,
	       IP addressing and number of transmitted packets and error rates.

	      * Accessibility to configured routes to external networks,
		including the default network route, checking the routers configured
		to give access to the network

	      * Proper host resolution, testing DNS resolution against a known host.

	      * Proper network connectivity, testing reachability of remote hosts using ICMP and simulating a web  connections	to  a  remote  web
	      server (the web server used for the tests can be configured through the environment, see below)

       The program does not need special privileges to run as it does not do any system change.

       However,  the behaviour of the program when running as an unprivileged user is not the same as running as system administrator (i.e. root).
       If the program is run as system administrator it will try to run some tools that are only available to it to speed up some of the tests.

       The program relies on the use of ip, netstat, ifconfig, arp and (when running as root) ethtool or mii-tool, to obtain information about the
       system's  networking  configuration (status of available interfaces and configured network routes). It also uses ping, host and nc (netcat)
       to do tests of the network connectivity and ensure that the host can connect to the Internet.

ENVIRONMENT

       The program will, by default, check www.debian.org and its associated web server. If you want to use a different check host you	can  setup
       the environment as follows:

       CHECK_HOST
	      The name of a host to use when testing DNS resolution.

       CHECK_IP_ADRESS
	      The IP address of the host defined in CHECK_HOST

       CHECK_WEB_HOST
	      The web server to use for testing purposes when testing network connectivity.

       CHECK_WEB_PORT
	      The web server port of server CHECK_WEB_HOST that will be used for testing.

EXIT STATUS

       The program will exit with error (1) if any of the network checks fail.

BUGS

       This  program  does  not  have  super cow powers so it is unable to fix the errors by itself. It is also unable to detect if the network is
       failing due to a local firewall policy been in place so make sure you check your system logs with dmesg (1) to detect if some of the active
       tests are being dropped due to your local firewall.

       Other known issues that might make the program not work reliable are:

	      * IPv6: The program does not yet explicitly handle IPv6 only hosts, some of the tests might be biased towards IPv4 and might fail in
	      IPv6 environments.

	      * Proxies: The program does not check network connectivity for hosts that connect through the Internet using  a  proxy  gateway  for
	      services.  The  program  might  report  issues in hosts using proxies even when these might connect to the Internet properly through
	      proxied services.

	      * Firewall environments: some of the tests rely on direct connectivity to external  hosts,  which  are  tested  using  ICMP  queries
	      (through	the  use  of ping. These tests might fail in hosts installed in networking environments with firewalls that block outbound
	      ICMP communication.

SEE ALSO

       ip (8), netstat (8), ifconfig (8), ethtool (8), mii-tool (8), ping (8), nc (1) and host (1).

AUTHOR

       network-test was written by Javier Fernandez-Sanguino for the Debian GNU/Linux distribution.

COPYRIGHT AND LICENCE

       Copyright (C) 2005-2011 Javier Fernandez-Sanguino <jfs@debian.org>.

       This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as  published	by
       the Free Software Foundation; either version 2, or (at your option) any later version.

       On Debian systems, a copy of the GNU General Public License may be found in /usr/share/common-licenses/GPL.

ifupdown-extra							  August 23 2011						   network-test(1)