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DNS Monitoring

Monitor your DNS records to ensure your domain configuration is correct and detect unauthorized changes or propagation issues.

Overview

DNS monitoring verifies that your domain's DNS records return the expected values. UptimeObserver queries DNS servers at regular intervals and alerts you when:

  • DNS records don't match expected values
  • DNS servers fail to respond
  • Records are missing or deleted
  • Unexpected changes are detected

This helps you catch DNS misconfigurations, hijacking attempts, and propagation failures before they impact your users.

Configuration Options

Hostname

Enter the domain or subdomain you want to monitor:

  • example.com. — Monitor root domain
  • www.example.com. — Monitor www subdomain
  • api.example.com. — Monitor API subdomain
  • mail.example.com. — Monitor mail subdomain

Record Type

Select the type of DNS record to monitor:

Record Type Description Common Use
A IPv4 address Primary domain/server IP mapping
AAAA IPv6 address IPv6-enabled servers
CNAME Canonical name (alias) Subdomains pointing to other domains
MX Mail exchange Email server configuration
TXT Text record SPF, DKIM, domain verification
NS Name server DNS delegation
SOA Start of authority DNS zone information
SRV Service record Service location (e.g., SIP, LDAP)
CAA Certification Authority Authorization SSL certificate issuance control
PTR Pointer record Reverse DNS lookups

Expected Value

Specify the value you expect the DNS record to return:

Record Type Example Expected Value
A 93.184.216.34
AAAA 2606:2800:220:1:248:1893:25c8:1946
CNAME example.com or cdn.example.net
MX mail.example.com or 10 mail.example.com
TXT v=spf1 include:_spf.google.com ~all
NS ns1.example.com

Partial Matching

For records with multiple values (like TXT or MX), you can specify a partial match to verify that a specific value is present.

DNS Server (Optional)

By default, UptimeObserver uses public DNS resolvers. You can specify a custom DNS server to:

  • Monitor a specific authoritative nameserver
  • Check propagation to particular DNS providers
  • Test internal DNS servers (if accessible)

Examples: - 8.8.8.8 — Google Public DNS - 1.1.1.1 — Cloudflare DNS - ns1.example.com — Your authoritative nameserver

Common Use Cases

Monitor Primary Domain IP

Ensure your domain points to the correct server:

  • Hostname: example.com
  • Record Type: A
  • Expected Value: 93.184.216.34

Monitor CDN Configuration

Verify your subdomain correctly points to your CDN:

  • Hostname: cdn.example.com
  • Record Type: CNAME
  • Expected Value: d1234.cloudfront.net

Monitor Email Configuration

Ensure email routing is correct:

  • Hostname: example.com
  • Record Type: MX
  • Expected Value: aspmx.l.google.com

Monitor SPF Record

Verify your SPF record for email deliverability:

  • Hostname: example.com
  • Record Type: TXT
  • Expected Value: v=spf1 include:_spf.google.com ~all

Monitor DKIM Record

Ensure DKIM signing is properly configured:

  • Hostname: google._domainkey.example.com
  • Record Type: TXT
  • Expected Value: v=DKIM1; k=rsa; p=...

Monitor Nameservers

Verify nameserver delegation:

  • Hostname: example.com
  • Record Type: NS
  • Expected Value: ns1.dnsprovider.com

Monitor Load Balancer Failover

Detect if a failover IP has been activated:

  • Hostname: app.example.com
  • Record Type: A
  • Expected Value: primary-server-ip

Why Monitor DNS?

Detect Unauthorized Changes

DNS hijacking and unauthorized changes can redirect your users to malicious sites. Monitoring alerts you immediately when records change.

Verify Propagation

After making DNS changes, monitor to confirm the new records have propagated to public DNS servers.

Prevent Downtime

Misconfigured DNS records can cause complete service outages. Catch configuration errors before they impact users.

Compliance & Security

For compliance requirements, DNS monitoring provides an audit trail and ensures security records (SPF, DKIM, DMARC) remain intact.

Troubleshooting

Record Not Found

  1. Verify the hostname — Ensure the domain/subdomain exists
  2. Check record type — Confirm you're checking the correct record type
  3. Wait for propagation — New records can take up to 48 hours to propagate

Value Mismatch

  1. Check for trailing dots — DNS records may include trailing dots (e.g., example.com.)
  2. Verify exact value — Ensure the expected value matches exactly, including case
  3. Multiple values — Some records return multiple values; ensure your expected value is one of them

DNS Server Timeout

  1. Check server accessibility — Ensure the DNS server is reachable from the internet
  2. Try a different DNS server — The specified server may be experiencing issues
  3. Use default resolvers — Remove custom DNS server to use UptimeObserver's default resolvers

TTL Considerations

DNS records have a Time-To-Live (TTL) value that affects how long records are cached. When making DNS changes:

  • Lower TTL before changes (e.g., 300 seconds)
  • Wait for old TTL to expire before monitoring new values
  • Increase TTL after changes are verified

Need Help?

If you need assistance configuring DNS monitoring, reach out using the "Need Help?" button on the bottom right corner or email us at support@uptimeobserver.com.