ifwatchdog
==========

This is a simple daemon that monitors the main network interface
configured in /etc/network/interfaces is up and has a non-zeroconf IP
address set. If not it calls ifup to bring the device up.

The intent is that this allows for robust network connectivity,
since transient failures that impede network configuration (e.g.,
unavailable DHCP server, no network cable plugged or duplicate
IP address on network) are eventually overcome, hence restoring
network connectivity.

The link layer is always left in the UP state and ifwatchdog assumes
that the ifup leaves no IPv4 addresses and no permanent IPv6 addresses
if it fails fully configuring the device (dynamic IPv6 addresses may
be left, normally they should).

A maximum time the main interface is allowed to have no assigned IP
address can be configured, after this time ifwatchdog reboots the
system. Likewise, a minimum time that main interface must keep an
assigned IP address can also be configured, if the address is lost
before this time elapses ifwatchdog reboots the system. These settings
are mainly intended to be used with USB modems which may sometimes
hang. Rebooting the system will usually reset these devices since the
power is cut to the USB port.

This program is proprietary of SpinetiX S.A. and may not be
freely redistributed.
