When a business website goes down, everyone's first thought is hackers. The real culprit, far more often, is a DNS record someone edited on a Friday afternoon.
The phone book of the internet
Computers find each other by numeric IP addresses. Humans prefer names. DNS (Domain Name System) is the global directory translating yourbusiness.com into the address of the server hosting it. Every visit, every email you receive, starts with a DNS lookup.
The records that run your business
You don't need to manage DNS yourself, but recognising the record types turns outage panic into a calm phone call:
- A record — points your domain to your web server's IP. Wrong A record = website down.
- CNAME — an alias pointing one name at another (
wwwat your main domain, or a verification name at a service like your email provider). - MX records — where your email gets delivered. Wrong MX = mail silently vanishing.
- TXT records — proofs and policies: SPF, DKIM, DMARC, site verifications.
Why changes take "up to 48 hours"
DNS answers get cached around the world so the system stays fast. When you change a record, caches expire on their own schedule — that's propagation. In practice most changes settle within an hour or two, but a cached old answer can linger. This is why good practice is to lower the cache time (TTL) before a planned migration.
How DNS actually breaks
The classic incidents we see:
- The redesign that killed email — someone repointed the domain to a new web host and copied only the A record, dropping the MX records. Website fine, email gone.
- Duplicate or conflicting records — old entries left behind by previous providers, fighting the new ones.
- The expired domain — no DNS at all (see our domain renewals guide).
- Typos — one wrong digit in an IP address takes everything down, with a delay that makes the cause hard to spot.
The safety rules
Keep DNS access restricted, document what each record is for, change one thing at a time, and snapshot the zone before touching anything — so any change can be reverted in seconds instead of reconstructed from memory.
We manage DNS for our clients' domains with zone backups and preview-before-apply imports, because we've cleaned up too many Friday-afternoon edits. If your zone is a mystery archive of old records, an audit is cheap peace of mind.