Domain not resolving

Your domain isn't translating to an IP address, so visitors are getting 'This site can't be reached' instead of your site. Match your error to the table below to find the right page.

Symptom

• The site's Domain routing card shows Failing. If the site can't be reached, the site card shows Down. If it still responds, the site card shows Alert once the DNS incident opens (two failing DNS checks in a row)
• Browsers show "This site can't be reached" with "ERR_NAME_NOT_RESOLVED" or "DNS_PROBE_FINISHED_NXDOMAIN" underneath
• Running dig example.com returns NXDOMAIN (the hostname has no records of any type), an empty answer (it has other record types but no A or AAAA) or SERVFAIL (the nameservers returned an error, or the resolver couldn't get an answer from them)
• The problem affects all visitors, so flushing your local cache doesn't help

What it means

Several different failures cause a domain to stop resolving. When a visitor types your URL into a browser, the browser first runs a DNS lookup: it asks the internet "what IP address does this domain point to?" If that lookup fails, the browser never attempts a connection and shows a generic error page.

A DNS lookup can fail for several reasons, each with a different fix. DomainDash marks the Domain routing card as Failing at its next DNS check. Identify which failure you're dealing with, then follow the guide for that issue.

Possible underlying issues

Match what you see in your browser or in DomainDash to the right page:

What you're seeing	Likely issue	Page
NXDOMAIN for one hostname, or NOERROR with an empty answer	No A/AAAA records	No A or AAAA records
NXDOMAIN for the whole domain, with records still at your DNS provider	Domain expired or suspended	Domain registration troubleshooting
SERVFAIL / DNS server timeout	Nameservers unreachable	Nameservers unreachable
Worked before, broken since a recent DNS change	DNS changes not propagating	DNS changes not propagating
DNS resolves but site won't load	Uptime-side problem, not DNS	Site is down

How to identify which issue you have

1. Open DomainDash and look at the DNS check status on the affected site's Domain routing card, then match the symptom you see (an empty answer, NXDOMAIN, SERVFAIL, or results that differ by location after a recent change) to the right page above.

2. Run dig from a terminal to see what's happening at the DNS level:

   dig example.com

   Replace example.com with your domain. An NXDOMAIN response means the hostname has no records of any type, for example a deleted www record or a domain that no longer exists. NOERROR with an empty ANSWER section means the hostname has other record types but no A or AAAA record. A SERVFAIL response means the nameservers returned an error, or the resolver couldn't get an answer from them. A timeout means you got no reply at all.

3. Try a different resolver to check whether the issue is global or resolver-specific:

   dig example.com @8.8.8.8
   dig example.com @1.1.1.1

   If one resolver returns records and another doesn't, DNS changes may still be propagating, because some resolvers have cached the old state. If all resolvers fail, the problem is with your domain's DNS configuration.

4. Check your domain registration with a WHOIS lookup:

   whois example.com

   Confirm the domain hasn't expired and that the nameservers listed match those in your DNS provider. A suspended or expired domain returns NXDOMAIN regardless of your DNS records.

How to verify

After applying the fix from the specific issue page:

1. Run dig example.com @8.8.8.8. The ANSWER section should contain an IP address.
2. Run dig example.com @1.1.1.1 to confirm across a second resolver.
3. In DomainDash, open the site's Domain routing page. Once your fix is live, the DNS check returns from Failing to Healthy at its next scheduled run.

Related

• DNS troubleshooting — the full list of DNS issues
• DNS health — how DomainDash runs DNS checks
• DNS resolution failed — the uptime-side equivalent when the HTTP check fails because of DNS
• How incidents work — how DomainDash confirms and notifies about DNS failures