To verify the connectivity of all IP addresses within a network segment, multiple approaches can be used. Two methods are presented here: a single-process implementation and a multi-process version.

Single-Process Ping Implementation (Sequential Processing)

#!/bin/bash
read -p "Enter the network portion of the IP address: " network_ip
for host in $(seq 1 254);
do
    {
        ping ${network_ip}.${host} -c 1 -s 1 2>&1 1>/dev/null && \
        echo -e "ping ${network_ip}.${host} is \033[32;49;1mreachable\033[39;49;0m" || \
        echo -e "ping ${network_ip}.${host} is \033[31;49;1munreachable\033[39;49;0m"
    }
done
echo "Scanning completed."

Multi-Process Ping Implementation (Using & and wait)

#!/bin/bash
read -p "Enter the network portion of the IP address: " network_ip
for host in $(seq 1 254);
do
    {
        ping ${network_ip}.${host} -c 1 -s 1 2>&1 1>/dev/null && \
        echo -e "ping ${network_ip}.${host} is \033[32;49;1mreachable\033[39;49;0m" || \
        echo -e "ping ${network_ip}.${host} is \033[31;49;1munreachable\033[39;49;0m"
    } &
done
wait
echo "Scanning completed."

Common ping parameters:

• -c count: Specifies the number of ping requests to send.
• -w deadline: Sets a timeout in seconds for the ping operation.
• -I interface: Defines the network interface to use for sending packets.
• -t ttl: Sets the Time To Live value for the packet.
• -s packetsize: Sets the size of the data payload in bytes.
• -W timeout: Waits for a reply for a specified time in seconds.

Summary: Since shell scripting does not support true multithreading, multi-process exceution is used instead. This is achieved by appending & to commands inside a loop to run them in the background. Using wait ensures that the script waits for all background processes to finish before proceeding.

Source: https://mefj.com.cn/lur3644.html