PRINTABLE FIELD NOTES
Common DNS records
Use this before an interview or during a focused review.
Common DNS records
DNS names are not URLs. A record cannot select an HTTP path.
| A / AAAA | Map a name to IPv4 / IPv6 addresses. Test both families when only some users fail. |
|---|---|
| CNAME | An alias to another DNS name. A CNAME is not an HTTP redirect. |
| MX | Mail exchange targets and preference. Web proxying is separate from mail delivery. |
| TXT | Text used by various verification and policy systems. SPF, DKIM and DMARC conventions use DNS records but are not interchangeable. |
| NS / SOA | Authoritative nameservers / zone administrative metadata. Compare registrar delegation with intended authoritative servers. |
| CAA | Constrains which certificate authorities may issue under the policy. It does not install a certificate. |
| SRV / PTR | Service location including port/priority conventions / reverse lookup from address to name. |
| TTL / negative answers | TTL controls cached lifetime. A lower TTL affects newly obtained data; existing caches can retain earlier values. Negative answers may be cached too. Resolvers configured to serve stale data may reuse expired answers when they cannot refresh them; TTL is not a guarantee of global convergence (RFC 8767). |