网络工具大全【2026】- IP地址查询与DNS解析原理详解

互联网通信流程：
你的设备 (192.168.1.100) → 路由器 → 互联网 → 目标服务器 (142.250.80.46)

二进制：11000000.10101000.00000001.00000001
十进制：192.168.1.1

IP地址：    192.168.1.100
子网掩码：  255.255.255.0
网络地址：  192.168.1.0
主机范围：  192.168.1.1 - 192.168.1.254
广播地址：  192.168.1.255

完整格式：2001:0db8:85a3:0000:0000:8a2e:0370:7334
简化格式：2001:db8:85a3::8a2e:370:7334

IP地址 → IP数据库查询 → 地理位置信息
  ↓           ↓              ↓
8.8.8.8   MaxMind/IP2Location   美国, 加利福尼亚, 山景城

用户输入：www.google.com
DNS解析：www.google.com → 142.250.80.46
浏览器访问：142.250.80.46

1. 浏览器缓存检查
      ↓ (未命中)
2. 操作系统缓存检查
      ↓ (未命中)
3. 本地DNS服务器查询
      ↓ (未命中)
4. 根域名服务器查询 → 返回.com服务器地址
      ↓
5. .com顶级域服务器查询 → 返回google.com服务器地址
      ↓
6. google.com权威服务器查询 → 返回www.google.com的IP
      ↓
7. 结果返回并缓存

example.com.    IN    A    93.184.216.34

example.com.    IN    AAAA    2606:2800:220:1:248:1893:25c8:1946

www.example.com.    IN    CNAME    example.com.
blog.example.com.   IN    CNAME    myblog.wordpress.com.

example.com.    IN    MX    10    mail1.example.com.
example.com.    IN    MX    20    mail2.example.com.

example.com.    IN    TXT    "v=spf1 include:_spf.google.com ~all"
_dmarc.example.com.    IN    TXT    "v=DMARC1; p=reject; rua=mailto:dmarc@example.com"

example.com.    IN    NS    ns1.example.com.
example.com.    IN    NS    ns2.example.com.

example.com.    IN    SOA    ns1.example.com. admin.example.com. (
                            2024010101 ; 序列号
                            7200       ; 刷新间隔
                            3600       ; 重试间隔
                            1209600    ; 过期时间
                            86400      ; 最小TTL
                            )

34.216.184.93.in-addr.arpa.    IN    PTR    example.com.

# 检查DNS解析是否正常
nslookup example.com
dig example.com

# 检查IP连通性
ping 93.184.216.34
traceroute example.com

# 检查特定DNS服务器
nslookup example.com 8.8.8.8

# 安全分析示例：检查可疑IP
def analyze_suspicious_ip(ip):
    info = get_ip_info(ip)
    risk_factors = []
    
    # 检查是否为已知VPN/代理
    if info.get('is_proxy'):
        risk_factors.append('使用代理/VPN')
    
    # 检查地理位置异常
    if info.get('country') in HIGH_RISK_COUNTRIES:
        risk_factors.append('高风险地区')
    
    # 检查ASN信誉
    if info.get('asn') in KNOWN_BAD_ASNS:
        risk_factors.append('可疑网络')
    
    return risk_factors

# 使用CNAME指向CDN
www.example.com.    CNAME    d1234.cloudfront.net.
static.example.com. CNAME    example.b-cdn.net.

# MX记录 - 指定邮件服务器
example.com.    MX    10    mx1.example.com.
example.com.    MX    20    mx2.example.com.

# SPF记录 - 防止邮件伪造
example.com.    TXT    "v=spf1 mx include:_spf.google.com -all"

# DKIM记录 - 邮件签名验证
selector._domainkey.example.com.    TXT    "v=DKIM1; k=rsa; p=..."

# DMARC记录 - 邮件策略
_dmarc.example.com.    TXT    "v=DMARC1; p=quarantine; rua=mailto:dmarc@example.com"

class IPValidator {
  static isValidIPv4(ip) {
    const pattern = /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
    return pattern.test(ip);
  }

  static isValidIPv6(ip) {
    const pattern = /^(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$|^::(?:[0-9a-fA-F]{1,4}:){0,6}[0-9a-fA-F]{1,4}$|^(?:[0-9a-fA-F]{1,4}:){1,7}:$|^(?:[0-9a-fA-F]{1,4}:){0,6}::(?:[0-9a-fA-F]{1,4}:){0,5}[0-9a-fA-F]{1,4}$/;
    return pattern.test(ip);
  }

  static isPrivateIP(ip) {
    const privateRanges = [
      /^10\./,
      /^172\.(1[6-9]|2[0-9]|3[0-1])\./,
      /^192\.168\./,
      /^127\./,
      /^169\.254\./
    ];
    return privateRanges.some(range => range.test(ip));
  }

  static getIPType(ip) {
    if (this.isValidIPv4(ip)) return 'IPv4';
    if (this.isValidIPv6(ip)) return 'IPv6';
    return 'Invalid';
  }
}

console.log(IPValidator.isValidIPv4('192.168.1.1')); // true
console.log(IPValidator.isPrivateIP('10.0.0.1')); // true
console.log(IPValidator.getIPType('2001:db8::1')); // IPv6

import dns.resolver

class DNSLookup:
    def __init__(self, nameserver='8.8.8.8'):
        self.resolver = dns.resolver.Resolver()
        self.resolver.nameservers = [nameserver]
    
    def query(self, domain, record_type='A'):
        try:
            answers = self.resolver.resolve(domain, record_type)
            return [str(rdata) for rdata in answers]
        except dns.resolver.NXDOMAIN:
            return {'error': '域名不存在'}
        except dns.resolver.NoAnswer:
            return {'error': f'没有{record_type}记录'}
        except Exception as e:
            return {'error': str(e)}
    
    def get_all_records(self, domain):
        record_types = ['A', 'AAAA', 'MX', 'TXT', 'NS', 'CNAME']
        results = {}
        for rtype in record_types:
            results[rtype] = self.query(domain, rtype)
        return results

dns_lookup = DNSLookup()
print(dns_lookup.query('google.com', 'A'))
print(dns_lookup.query('google.com', 'MX'))
print(dns_lookup.get_all_records('example.com'))

package main

import (
    "encoding/json"
    "fmt"
    "net/http"
)

type IPInfo struct {
    IP       string  `json:"ip"`
    Country  string  `json:"country"`
    Region   string  `json:"region"`
    City     string  `json:"city"`
    ISP      string  `json:"isp"`
    Lat      float64 `json:"lat"`
    Lon      float64 `json:"lon"`
    Timezone string  `json:"timezone"`
}

func lookupIP(ip string) (*IPInfo, error) {
    url := fmt.Sprintf("http://ip-api.com/json/%s", ip)
    resp, err := http.Get(url)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    var info IPInfo
    if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
        return nil, err
    }
    return &info, nil
}

func main() {
    info, err := lookupIP("8.8.8.8")
    if err != nil {
        fmt.Println("查询失败:", err)
        return
    }
    fmt.Printf("IP: %s\n国家: %s\n城市: %s\nISP: %s\n",
        info.IP, info.Country, info.City, info.ISP)
}