DNS 查询
A、AAAA、MX、TXT、NS、CNAME、SOA 与 CAA 记录，实时解析。
改为输入 IP 地址即可查询其反向 DNS 名称。
DNS is the directory that turns a hostname into an address, and a good deal else besides. This page resolves the records a hostname publishes — A and AAAA for addresses, MX for mail, NS for delegation, TXT for everything from domain verification to mail policy, plus CNAME, SOA and CAA — and links each answer through to the address behind it.
What each record type is for
A and AAAA carry IPv4 and IPv6 addresses. MX names the servers that accept mail for the domain, in priority order. NS names the servers authoritative for the zone. TXT holds free-form strings, which is why SPF, DKIM and DMARC policies all live there. CNAME points one name at another. SOA carries the zone's serial number and timing parameters. CAA states which certificate authorities may issue for the domain.
Resolved live, from our server
These queries run at the moment you ask, from our resolver, which means the answer reflects the current state of the zone rather than a cached copy of it. It also means what you see is what our network sees: a domain using geographic or split-horizon DNS can legitimately answer differently for you than for us.
Reverse DNS is the other direction
Reverse DNS maps an address back to a name, using the PTR record under in-addr.arpa or ip6.arpa. It is published by whoever controls the address block, so it can claim anything — which is why we also check whether the claimed name resolves forward to the same address. That check is what mail servers rely on, and a name that fails it is worth nothing.
常见问题
Why do I get a different answer than my own computer does?
Your resolver may hold a cached copy from before a change, or the domain may serve different answers by region. We query live from our own network, so a difference usually means caching on your side or geographic DNS on theirs.
What is a CAA record and should I have one?
It lists the certificate authorities allowed to issue certificates for your domain. Any CA is required to check it before issuing. It is cheap to publish and it closes off a real class of mis-issuance, so yes.
Why does a domain have several MX records?
For redundancy. The priority number decides the order: a sending server tries the lowest first and falls back through the rest. Equal priorities are used to spread load.