DNS lookup
DNS lookup件any domain: see its IP addresses、mail servers, 名称 servers, TXT、other records.
Queries go 至 Cloudflare’s public DNS over HTTPS service when you press the button.
关于DNS lookup
DNS lookup件any domain: see its IP addresses、mail servers, 名称 servers, TXT、other records.
属于 SmartCalcy“数据与网络”板块。它在你的浏览器中运行，无需账号，使用你自己的货币和单位（可在页面顶部更改），所给结果仅为估算、仅供参考，因此在依赖结果之前请查阅官方指引。
如何使用DNS lookup
它计算什么，何时使用
Looks up the DNS records a domain name: its IPv4 和 IPv6 addresses (A 和 AAAA)、mail servers (MX), 名称 servers (NS), text records (TXT), aliases (CNAME), 区间 详情 (SOA)、certificate rules (CAA). Use it 至 check that a domain points where you expect、or 至 debug email、website set-up.
使用步骤
- Type a domain 名称 such as 示例.com.
- Choose a record type, 或 保留 “All common records”.
- Press “Look up DNS”.
- Read 每件 record card. TTL 是 how many 秒 the answer may be cached.
各输入项的含义
- Domain 名称 – The domain 至 look up. Web addresses are cleaned 至 the domain, so https://example.com/page also works.
- Record type – One record type, 或 all the common ones.
如何阅读结果
- A 和 AAAA – The IPv4 和 IPv6 addresses the 名称 点数 到.
- MX – Mail servers, with a priority 数字. Lower 数字 are tried first.
- NS, TXT, CNAME, SOA, CAA – 名称 servers、text records such as SPF, aliases, 区间 authority、which certificate authorities may issue certificates.
公式
否 calculation. The browser asks Cloudflare’s public DNS over HTTPS service件each record type 和 shows the answers it gets. TTL 是 seconds that resolvers may cache an answer. 的 the time
计算示例
A lookup example.com returns an A record with an IPv4 address、MX records件mail,、TXT records including its SPF policy.
假设与局限
- Answers come from a public resolver 和 may be cached件up 至 the TTL, so a change made a few minutes ago may not show yet.
- The lookup 是 made when you press the button.
- Only the common record types are offered.
常见错误
- 第 Typing a full web address with a pa 次 和 expecting records件the page. DNS works on domain names only.
- Expecting a 变化 至 显示 immediately. Caches hold old answers 直到 the TTL runs out.
- Looking up a subdomain you have not created, which returns 否 records.
常见问题
What 是 a DNS record?
An entry that tells the internet something about a domain, such as which server hosts its website 或 handles its email.
What does TTL 平均值?
时间 至 seconds. It 的 live, 是 how long other servers may reuse an answer before asking again.
Why are there several MX records?
They give backup mail servers. The one with the lowest priority 数字 是 tried first.
What does NXDOMAIN 平均值?
The domain does not exist, so check the spelling.
罐 I look up an MX record only?
the record type list. 的 是. Choose MX