DNS查询

A DNS lookup queries the Domain Name System to find the records associated with a domain name. These records map domain names to IP addresses (A/AAAA records), mail servers (MX records), text verification (TXT records), name servers (NS records), and more. DNS is essentially the phone book of the internet.

The most common DNS record types are: A (maps domain to IPv4 address), AAAA (maps domain to IPv6 address), MX (specifies mail servers), TXT (holds text information like SPF, DKIM, and verification records), NS (specifies authoritative name servers), SOA (contains zone authority information), and CNAME (creates an alias pointing to another domain).

Checking DNS records is useful for troubleshooting email delivery issues (MX records), verifying domain ownership (TXT records), debugging website connectivity problems (A/AAAA records), checking DNS propagation after changes, and auditing your domain security configuration (SPF, DKIM, DMARC in TXT records).

DNS propagation typically takes anywhere from a few minutes to 48 hours, depending on the TTL (Time To Live) value set on the records. Lower TTL values mean faster propagation. Most changes propagate within 1-4 hours. You can check the TTL of existing records using this tool to estimate propagation time.