NETCHECK

netcheck - monitor network connectivity to select hosts

netcheck [−u] [−v] [−l logfile] [−c conffile] [−t percent] [−m] [−n] [−o]

This perl script monitors the state of the network connection between the host running the script and specified remote hosts. It uses ping(1) and traceroute(1) for this purpose. Output, by default, goes to both STDOUT and to a logfile. In addition, packet losses above a threshold value cause email to be sent to spcified email addresses. Netcheck finds what hosts to monitor, and who to send mail to, in a configuration file, netcheck.conf.

Netcheck requires that the environment variable LDMHOME be set to the directory containing both the etc and logs directory containing the configuration file and log file respectively. If this variable is not set netcheck exits.

Output to both STDOUT and/or the log file may be turned off by command line switches, as may the email notification. Also, the packet loss threshold may be adjusted via a command line argument.

−u

Usage. When present, causes a usage message to be printed and netcheck exits.

−v

Verbose flag. When present the individual packet statistics from ping(1) are printed. By default, only the ping(8) summary is displayed.

−l logfile

The path name of a file to be used as the log file for the process. The default is to use $LDMHOME/logs/netcheck.log.

−c conffile

The path name of the configuration file containing the hosts to be checked and the list of names for email. The default is to use $LDMHOME/etc/netcheck.conf.

−t percent

The packet loss percentage threshold. Packet losses greater than the threshold will cause an email warning to be sent. The default is 20%.

−m

Mail flag. When present turns off warning email.

−n

STDOUT flag. When present supresses output to STDOUT. Should be used when running netcheck out of cron(1).

−o

Log output flag. When present supresses output to the logfile.

Netcheck requires that traceroute(1) be installed and executable by root. Usually this means that root will own traceroute(1), but it will be installed setuid.

ping(1), traceroute(1)