方法一：寫一個shell指令碼，迴圈ping網段內的每一個ip

編輯並儲存getAllHosts.sh指令碼，內容是：

#!/bin/bash
NETWORK=$1
for HOST in $(seq 1 254)
do
    ping -c 1 -w 1 $NETWORK.$HOST &>/dev/null && result=0 || result=1
        if [ "$result" == 0 ];then
            echo -e "\033[32;1m$NETWORK.$HOST is up! \033[0m"
        #echo "$NETWORK.$HOST" >> /home/y/AllHosts_up.txt
 

        else
            echo -e "\033[;31m$NETWORK.$HOST is down!\033[0m"
        #echo "$NETWORK.$HOST" >> /home/y/AllHosts_down.txt
    fi
done

用法：sh getAllHosts.sh <網段>，如：

y@ubuntu:~$ sh  getAllHosts.sh 172.16.247

方法二：用nmap工具包掃描

namp是Linux下的網路掃描和嗅探工具包，可用於掃描網上電腦開放的網路連線埠

如：

[email protected]
 
:~$ nmap -sT  172.16.247.0/24

Starting Nmap 7.60 ( https://nmap.org ) at 2018-08-02 07:20 PDT
Nmap scan report for _gateway (172.16.247.2)
Host is up (0.0036s latency).
Not shown: 999 closed ports
PORT   STATE SERVICE
53/tcp open  domain

Nmap scan report for ubuntu (172.16.247.138)
Host is up (0.0013s latency).
All
 
 1000 scanned ports on ubuntu (172.16.247.138) are closed

Nmap done: 256 IP addresses (2 hosts up) scanned in 2.63 seconds

可以看到，根據nmap掃描報告，找到2臺主機，一臺是172.16.247.2(是閘道器)，另一臺是172.16.247.138(是本機自己)，最後提示共掃描了256個ip地址，2臺主機是線上狀態。