Help with Channels

package main

import (
    "fmt"
    "net"
    "time"
)

func isPortOpen2(dest_host string, port int, out chan string) {
    // defer close(out)
    // If I do this, it closes the channel after the first execution of function which makes sense.
    // But I dont do this, when I print the output I need to send ctrl c to exit the program.


    timeout := time.Second * 1
    target := fmt.Sprintf("%s:%d", dest_host, port)

    conn, err := net.DialTimeout("tcp", target, timeout)

    if err != nil {
        out <- fmt.Sprintf("[%s]\t %s", "CLOSED", target)
    }

    if conn != nil {
        out <- fmt.Sprintf("[%s]\t %s", "OPEN", target)
    }
}

func main() {

    out := make(chan string)

    hosts := []string{"google.com", "reddit.com", "duckduckgo.com", "python.org"}
    ports := []int{123, 43, 534, 325, 12, 443, 8080, 34, 5455, 23543, 9432, 843}

    for _, host := range hosts {
        for _, port := range ports {
            go isPortOpen2(host, port, out)
        }
    }

    for i := range out {
        fmt.Println(i)
    }
}