DNS monitoring

One bad DNS record can take your whole business offline. Watch it, so it never does.

DNS is the switchboard for your entire site and email. PulseStack watches the record you choose against the value you expect, and alerts you the moment it changes - catching accidental edits, failed changes and modifications you never authorised.

Free plan, no card required - 5 monitors and HTTP checks to start. DNS monitoring on every paid plan.

Live DNS resolution via Google and Cloudflare - PulseStack watches these records for unexpected changes.

6
record types you can watch
A, AAAA, CNAME, MX, TXT and NS
30s
fastest check interval
On the Enterprise plan
8
native alert channels
From email to PagerDuty
Multi
location resolution
No single resolver fools it

A watcher pinned to the value you expect

Most monitoring tells you a page is down after the damage is done. A DNS monitor works one layer earlier. You tell PulseStack what a record should resolve to, and we compare the live answer to that baseline on every check.

When the two stop matching - an edit, a failed change, an unexpected modification - you know within one interval, not when a customer emails to say the site is gone.

A

Points your root domain at a server IP. Edit the wrong octet and the whole site drops.

AAAA

The IPv6 equivalent of an A record. Easy to forget, easy to leave stale.

CNAME

Aliases one hostname to another. A broken CNAME breaks subdomains and CDNs.

MX

Routes your email. A single wrong MX priority and inbound mail bounces.

TXT

Holds SPF, DKIM and verification strings. Lose one and email lands in spam.

NS

Delegates authority for your zone. Change these and you can lose the domain entirely.

What happens when DNS breaks

DNS failures are quiet. Nothing errors in your app - the traffic simply never arrives. Here is how it shows up.

01

The site vanishes

An A record edited to the wrong IP resolves to nothing, or to someone else's server. Visitors see a blank page or a stranger's site, and nothing in your app logs explains why - because the traffic never reached you.

02

Email silently bounces

A fat-fingered MX priority or a dropped SPF TXT record and inbound mail starts bouncing while outbound lands in spam. You often only find out when a customer phones to ask why their emails went unanswered.

03

A migration half-lands

You repoint DNS for a cutover, one record does not propagate as planned, and half your users hit the old host while half hit the new one. Sessions break, carts empty, and the rollback is a guessing game.

04

A change you never made

A compromised registrar login or a colleague in the wrong panel rewrites a record. Without a watcher on the expected value, an unexpected DNS modification can sit live for hours before anyone notices.

Put a watcher on your DNS in under two minutes

Enter a hostname, pin the expected value, and you are covered.

From zero to alerted in four steps

1

Add a DNS monitor

Enter the hostname and choose the record type you care about - A, AAAA, CNAME, MX, TXT or NS.

2

Set the expected value

Tell PulseStack what the record should resolve to. That becomes the baseline every check is measured against.

3

We watch on your interval

PulseStack resolves the record from multiple locations on your plan's check interval and compares it to your expected value.

4

You get alerted on drift

The moment the live record stops matching, we fire an alert down every channel you've wired up.

The check, in plain terms

Every interval, PulseStack resolves your record from multiple locations and diffs the live answer against your expected value. Match, and the monitor stays green. Drift, and it flips - and the alert goes out.

A consecutive-failure threshold means one flaky resolver never wakes you at 3am. We only escalate once the drift is real.

pulsestack - dns monitor
# monitor: pulsestack.co.uk (A)
expected 203.0.113.10
resolved 203.0.113.10 via lon,fra,nyc
result MATCH - monitor up
# 09:41 - unexpected change detected
expected 203.0.113.10
resolved 198.51.100.4
result DRIFT - alerting slack, pagerduty

Everything in a DNS monitor

Watch A, AAAA, CNAME, MX, TXT and NS records
Pin an expected value and alert the instant it drifts
Multi-location resolution so a single flaky resolver never fools you
Consecutive-failure threshold to strip out transient noise
Alerts across all 8 native channels
Incident history with a timeline of every change
Maintenance windows to mute planned cutovers
Public status pages that reflect resolver health

DNS is one of eight monitor types

Watch DNS alongside everything else that keeps you online - one account, one dashboard, one set of alert rules.

HTTP

Watch status codes, response time and page content.

Keyword

Confirm a word is present - or absent - in the response.

TCP Ping

Check a host answers at the network level.

Port

Verify a specific service port is open and listening.

API

Probe a JSON endpoint with custom request headers.

Heartbeat

Get alerted when a scheduled job stops checking in.

DNS

Watch a record against an expected value and catch every change.

Domain Expiry

Track registration dates so a domain never lapses unnoticed.

Drift, and every channel lights up

Route DNS alerts to wherever your team already lives. Eight native channels, no glue code.

EmailSMSSlackMicrosoft TeamsDiscordPagerDutyTelegramWebhooks

SMS and voice available as an add-on, included on Team and Enterprise.

Who leans on DNS monitoring

Agencies managing client zones

You hold DNS for dozens of clients across as many registrars. A DNS monitor per zone means you hear about a bad edit before the client does - and can prove you caught it.

Teams mid-migration

Cutovers live and die on DNS. Pin the expected records for the new host and watch propagation land in real time instead of refreshing dig in a terminal.

Ops guarding email deliverability

SPF, DKIM and MX live in DNS. Watch the TXT and MX records that keep mail flowing and get paged the second one is rewritten.

Stop finding out about DNS changes from your customers

Pin the value, set the threshold, and let PulseStack keep watch.

Three honest ways to watch DNS

Checking by hand

The dig-in-a-terminal approach

  • - Only catches a change if you happen to look
  • - No alerting, no history, no record
  • - One resolver's cache can mislead you

A PulseStack DNS monitor

Pinned, multi-location, always on

  • + Compares live records to your expected value every interval
  • + Alerts across 8 channels with a noise threshold
  • + Multi-location resolution and full incident history

Uptime-only monitoring

Watching the page, not the plumbing

  • ~ Only reacts once the site is already down
  • ~ Blind to email records like MX and TXT
  • ~ No sense of what the record should have been

PulseStack does the middle column - and the uptime column - from one account.

DNS monitoring questions

What is DNS record monitoring?+

DNS record monitoring continuously checks the DNS records associated with your domains and alerts you when any record changes. PulseStack™ queries authoritative nameservers for A, AAAA, MX, NS, CNAME, TXT, and SOA records at configurable intervals. When a record value differs from the previous check, you receive an alert with the old and new values. This catches unauthorised changes, misconfigurations, and DNS hijacking attempts before they affect your users.

Why do DNS records change unexpectedly?+

Unexpected DNS changes happen for several reasons. A compromised registrar account allows an attacker to modify records directly. Misconfigured infrastructure-as-code deployments can overwrite production records during a staging push. Shared hosting panels sometimes allow one tenant to affect another's DNS. CDN or load balancer migrations that do not update all records leave orphaned entries. Third-party services that you granted DNS access to may modify records during their own updates. Each scenario produces different symptoms but the same outcome: broken services.

Which DNS records should I monitor?+

At minimum, monitor A records (they point your domain to your server), MX records (they route your email), and NS records (they control who is authoritative for your zone). For comprehensive coverage, also monitor CNAME records used for subdomains and CDN routing, TXT records that contain SPF, DKIM, and DMARC policies for email authentication, and SOA records that indicate zone transfer and refresh settings. PulseStack monitors all record types by default.

How does DNS monitoring protect email deliverability?+

Email depends on three DNS record types: MX records that tell sending servers where to deliver mail, SPF records in TXT entries that define which servers are authorised to send on your behalf, and DKIM records that provide cryptographic signatures for message verification. If any of these records are deleted, modified, or misconfigured, your outbound email gets rejected or flagged as spam by receiving servers. PulseStack detects changes to all email-related DNS records and alerts you before deliverability degrades.

What is DNS hijacking and how does monitoring detect it?+

DNS hijacking occurs when an attacker modifies your DNS records to redirect traffic to servers they control. This can happen through compromised registrar accounts, exploited DNS management APIs, or BGP route hijacking that intercepts queries to your authoritative nameservers. PulseStack detects hijacking by comparing current DNS responses against known-good baselines. If your A record suddenly points to an IP address that is not yours, or your NS records change to nameservers you do not control, alerts fire immediately.

How quickly does PulseStack detect DNS changes?+

Detection speed depends on your configured check interval. The free plan supports 3-minute intervals, meaning changes are detected within 3 minutes at most. Paid plans support 30-second intervals for near-real-time detection. Each check queries authoritative nameservers directly, bypassing DNS caches, so PulseStack sees changes as soon as they propagate to the authoritative servers rather than waiting for cached records to expire.

Can I monitor DNS records for subdomains?+

Yes. Each subdomain has its own independent DNS records and can be monitored separately. You can monitor www.example.com, api.example.com, mail.example.com, and staging.example.com as individual monitors. This is important because subdomains often point to different services, CDNs, or third-party platforms that can change independently. A forgotten subdomain pointing to a decommissioned service is a common subdomain takeover vulnerability.

What is DNS propagation and why does it matter for monitoring?+

DNS propagation is the process of DNS changes spreading across the global network of recursive resolvers. When you update a DNS record, the change appears on your authoritative nameserver immediately but cached copies at ISP resolvers worldwide continue serving the old record until their TTL expires. This means different users see different DNS responses during propagation. PulseStack queries authoritative nameservers directly to detect changes at the source, regardless of propagation state.

Does DNS monitoring work with Cloudflare, Route 53, and other DNS providers?+

Yes. PulseStack monitors DNS records regardless of which DNS provider hosts your zone. Cloudflare, AWS Route 53, Google Cloud DNS, Azure DNS, DigitalOcean DNS, Namecheap, GoDaddy, and any standards-compliant nameserver are supported. PulseStack queries the authoritative nameservers listed in your domain's NS records, so it works with any provider without requiring API access or account credentials.

Can I use the free DNS lookup tool without signing up?+

Yes. The DNS lookup tool on this page is completely free with no account required. Enter any domain to see all A, AAAA, MX, NS, CNAME, TXT, and SOA records resolved via Google and Cloudflare DNS servers. For continuous monitoring with automated change detection and alerts, sign up for a free account with 50 monitors included.

How does DNS monitoring differ from uptime monitoring?+

Uptime monitoring checks whether your website or API responds to HTTP requests. DNS monitoring checks whether your domain's DNS records contain the correct values. You can have correct DNS records but a crashed web server, or a healthy web server but misconfigured DNS. Both failure modes produce the same symptom to users, but they require different diagnostic approaches. Running both DNS and HTTP monitoring gives you complete visibility into whether the problem is at the DNS layer or the application layer.

What happens if my authoritative nameserver goes down?+

If your authoritative nameservers become unreachable, DNS resolvers worldwide will continue serving cached records until their TTL expires. After that, resolution fails entirely and your domain becomes unreachable for all services including web, email, and API. PulseStack detects nameserver unavailability during its regular checks and alerts you before cached records expire. This gives you a window to restore the nameserver or switch to backup nameservers before users are affected.

Your DNS holds up everything. Give it a watcher.

Add a DNS monitor, pin the expected value, and never be the last to know about a change again. Start free, no card required.