DNS & Domain
DNS
Domain Name System
The Domain Name System (DNS) is the distributed database that translates human-readable domain names like lemwatch.com into the IP addresses computers use to route traffic. It is the address book of the internet.
Part of DNS monitoring — the full answer, the facts and the alternatives in one place.
In depth
DNS resolution involves multiple steps: the recursive resolver queries root servers, then top-level-domain servers (.com), then authoritative servers for the domain, then caches the result for the TTL specified by the record. Common record types include A (IPv4), AAAA (IPv6), CNAME (alias), MX (mail server), TXT (arbitrary text, used for SPF/DKIM/DMARC verification), and NS (authoritative servers).
DNS changes propagate based on TTL — a 24-hour TTL means it can take a full day for changes to fully reach every resolver worldwide.
Why it matters
An accidental DNS change can take an entire site offline. Monitoring DNS records for unauthorised modifications — and alerting on changes to A, MX, NS, and CNAME records — is essential for any business-critical domain.
How Lemwatch helps with dns
Lemwatch monitors dns continuously and alerts you the moment something changes.
DNS monitoring →Related terms
Domain Expiry
Domain expiry is the date a domain registration lapses. After expiry, the domain enters a grace period; after …
SPF
Sender Policy Framework (SPF) is an email authentication standard that publishes the list of IP addresses auth…
DMARC
DMARC is an email authentication protocol that lets a domain owner publish a policy specifying how mailbox pro…
RDAP
Registration Data Access Protocol (RDAP) is the modern replacement for WHOIS. It returns structured JSON data …
Browse the full Lemwatch monitoring glossary (47 terms).