watchdog checking network interface

ifwatch

#!/bin/bash
#
# watchdog checking network interface

if [ $# -ne 1 ]; then
    cat <<HERE
usage:
    ifwatch eth0
HERE
    exit 1
fi
interface=$1

let err_count=0
while true; do
    while true; do
        ip address list "$interface" | grep "inet " > /dev/null
        result=$?
        if [ $result -ne 0 ]; then
            logger -s -p crit -t ifwatch "no inet found, err_count=$err_count"
            err_count=$(($err_count+1))
        else
            err_count=0
        fi
        if [ $err_count -gt 3 ]; then
            logger -s -p crit -t ifwatch "no inet found, err_count=$err_count, rebooting"
            reboot
        fi
        sleep 60
    done
done

# eof.