Ping Drop Capture Script for Linux

This script will ping specified host periodically and display the result. You can save results to a logfile. I will show you how you can run this script unattended so that output will keep logging in a file even-if you close your ssh/telnet session.

This will help you capture intermittent ping drops between two nodes.

vi myPingScript.sh  #!/bin/bash host=$1 if [ -z $host ]; then     echo "Usage: `basename $0` [HOST]"     exit 1 fi while :; do result=`ping -W 1 -c 1 $host | grep 'bytes from '` if [ $? -gt 0 ]; then echo -e "`date +'%Y/%m/%d %H:%M:%S'` - host $host is \033[0;31mdown\033[0m" sleep 1 # avoid ping rain else echo -e "`date +'%Y/%m/%d %H:%M:%S'` - host $host is \033[0;32mok\033[0m -`echo $result | cut -d ':' -f 2`" sleep 1 # avoid ping rain fi done

The script will send one ping every second and display the result on screen. You can increase the sleep time as per your requirement by changing "sleep 1". For example "sleep 5" will send one ping every 5 seconds.

Make the script executable by following command

chmod +x myPingScript.sh 

USAGES

./myPingScript.sh 10.40.2.34

 OR

./myPingScript.sh google.com

To capture result in a log file use linux output redirection

./myPingScript.sh 10.40.2.34 >> myLogFile.txt &

If you are interested in capturing only down times then use grep.

./myPingScript.sh 10.40.2.34 | grep down >> myLogFile.txt

To get the output on the console AND in a file

./myPingScript.sh 10.40.2.38 | tee myLogFile.txt

Ensure that you have write permissions on filepath.

Running script in background

Running script with nohup will keep it running in background.

nohup command line-utility allows to run command/process or shell script that can continue running in the background after you log out from a shell.

nohup ./myPingScript.sh 10.40.2.38 | grep down >> myLogFile.txt

 

 

Script to log RTT crossing threshold

 

vi myPingScript.sh  #!/bin/bash if [ -z "$1" ]; then echo "Usage: `basename $0` [HOST] [RTT] [sleepTime]" echo "sleepTime can be in fraction seconds for example 0.1" exit 1 else echo "Starting Ping" host=$1 fi if [ -z "$2" ]; then echo "print result when RTT is greater then 0" RTT="0" else RTT=$2 echo "print result when RTT is greater then $RTT" fi if [ -z "$3" ]; then echo "sleep for 1 sec after each ping" sleepTime="1" else sleepTime=$3 echo "sleep for $sleepTime sec after each ping" fi while :; do result=`ping -W 1 -c 1 $host | grep 'bytes from '` if [ $? -gt "0" ] then echo -e "`date +'%Y/%m/%d %H:%M:%S'` - host $host is \033[0;31mdown\033[0m" sleep 1 # avoid ping rain else pingtime=`echo $result | cut -d ':' -f 2 | cut -d '=' -f 4 | cut -d " " -f 1` #echo $pingtime if (( $(echo "$pingtime > $RTT" |bc -l) )); then echo -e "`date +'%Y/%m/%d %H:%M:%S'` - host $host is \033[0;32mok\033[0m -`echo $result | cut -d ':' -f 2`" fi sleep $sleepTime # avoid ping rain fi done

myPingScript.sh [host] [min RTT] [sleepTime]
it will print output if RTT is more then specified value
sleepTime is in seconds and can be in decimals like 0.1

# ./myPingScript.sh 8.8.8.8 33.1 0.5