Scan port with nmap, use 11211(memcached) and 6379(redis) as example

scan_port.sh

#!/bin/bash

if [ $# -lt 1 ];then
    echo "usage:$0 iplist"
    exit 1
fi

iplist=$1

i=0

while read line
do
    if [ -z "$line" ];then
        continue;
    fi

    echo $line
    # each line is a single ip
    #nmap -Pn -sT -p23-65535 $line | grep 'open'
    nmap -Pn -sT -p11211,6379 $line | grep 'open'

    let i+=1
    # sleep seconds to control the rate
    k=$(($i%20))
    if [ $k -eq 0 ];then
        echo ""
        echo "sleep..."
        sleep 3
    fi
    
done < "$iplist"

nmap -Pn -sT -p11211,6379 -iL iplist.file