解析 and understand DNS records
DNS records 映射域 names 到 IPs, mail servers, 和其他数据. Learn , AAAA, CNAME, MX, TXT, NS, 和 SOA 记录 types.
- 1
DNS (域 Name System) translates 域 names 到 IP addresses. Record types: (IPv4 address), AAAA (IPv6), CNAME (alias 到另一个 name), MX (mail 服务器具有 priority), TXT (arbitrary 文本, used 为 SPF/DKIM/DMARC), NS (name 服务器), SOA (启动的 authority), PTR (反转 lookup), SRV (服务 locator).
- 2 IP 信息查询器 →
Look 上 IP address 到理解其 反转 DNS 和网络信息. 此 complements DNS forward lookups — given IP, 查找 hostname; given hostname, 查找 IP.
- 3 URL 解析器 →
解析 a domain name from a URL to extract the hostname for DNS lookup. The hostname is what DNS resolves — the URL may include port, path, and query that are not part of DNS.
常见问题
- 什么是 差集之间和 CNAME?
- 记录 maps name directly 到 IP address. CNAME maps name 到另一个 name (alias). Use records 为根 domains (示例.com) 和 direct mappings. Use CNAME 为 aliases (www.示例.com → 示例.com). name cannot 有两者和 CNAME records.
- 什么是 TXT records used 为?
- TXT records 存储 arbitrary 文本, 通常 used 为: SPF (sender 策略框架 — 哪个 IPs 能够发送 email), DKIM (email 签名键), DMARC (email 策略), 域验证 (Google, Microsoft), 和 MTA-STS. 它们是 Swiss Army knife 的 DNS.