2. 编写代码实现ICMP的活跃主机发现，要求探测的目标主机实现固定和手工输入（单个或区间主机）和实现区间主机自动化ICMP探测，共编写三种

在编写代码实现ICMP活跃主机发现时，你可以利用Python等编程语言中的socket模块来模拟ICMP Echo Request（ping请求）。这里是一个简单的示例，展示了如何分别实现对单个主机、手动输入的区间主机以及自动化的区间主机探测：

1. **单个主机检测**:

import socket

def ping_host(ip):
    # 创建ICMP echo request消息
    icmp = socket.getprotobyname('icmp')
    packet = bytearray(socket.htons(8)) + socket.inet_aton(ip) + bytearray(0)

    sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
    sock.sendto(packet, (ip, 1))

    # 接收响应并计算延迟
    data, addr = sock.recvfrom(64)
    response_time = round((len(data)-8)/8000, 3)
    return response_time if data else None

# 调用函数，例如 ping_host('192.168.1.1')

2. **手动输入区间主机探测**:

def range_ping(start_ip, end_ip):
    for ip in range(start_ip, end_ip+1):
        response_time = ping_host(ip)
        if response_time is not None:
            print(f"IP {ip}: Response time - {response_time} ms")

# 用户输入范围，如 range_ping('192.168.1.1', '192.168.1.10')

3. **自动化区间主机探测（使用列表）**:

def auto_range_ping(hosts_list):
    results = {}
    for host in hosts_list:
        response_time = ping_host(host)
        if response_time:
            results[host] = response_time
    return results

# 输入主机列表，如 hosts_list = ['192.168.1.1', '192.168.1.5', '192.168.1.7']
results = auto_range_ping(hosts_list)