#!/bin/bash

# Define the target host to test MTU
target_host="google.com"
# Define the maximum MTU size to test
max_mtu=1500
# Define the step size for MTU testing
step=10
# Define the timeout for each ping command
timeout=1
# Define the number of packets to send for each ping
count=15

# Function to perform ping with a specific MTU size
function ping_with_mtu {
    ping -M do -c $count -W $timeout -s $1 $target_host > /dev/null 2>&1
    return $?
}

# Function to test MTU for a specific size
function test_mtu {
    ping_with_mtu $1
    return $?
}

# Iterate through MTU sizes and test them
for (( mtu=$max_mtu; mtu>=1200; mtu-=$step ))
do
    test_mtu $mtu
    if [ $? -eq 0 ]; then
        echo "MTU $mtu works fine. (Continuous)"
    else
        echo "MTU $mtu does not work. (Fragmented)"
    fi
done