Cannot open a Plesk website: ERR_NAME_RESOLUTION_FAILED; Host example.com not found: 2(SERVFAIL)

Symptoms

• A Plesk-hosted website shows either of the following errors:

  ERR_NAME_RESOLUTION_FAILED

  ---

  ERR_NAME_NOT_RESOLVED

• Domain name cannot be resolved with SERVFAIL error:

  # host example.com 8.8.8.8
  Using domain server:
  Name: 8.8.8.8
  Address: 8.8.8.8#53
  (…)
  Host example.com not found: 2(SERVFAIL)

• Tracing the DNS query shows that authoritative NS servers cannot be accessed:

  # dig +short +trace example.com @8.8.8.8
  NS g.root-servers.net. from server 8.8.8.8 in 64 ms.
  (…)
  NS c.root-servers.net. from server 8.8.8.8 in 64 ms.
  dig: couldn’t get address for ‘ns1.examplens.com’: no more

• Authoritative NS servers do not have A records:

  # host ns2.examplens.com
  Host ns2.examplens.com not found: 3(NXDOMAIN)

  # host ns1.examplens.com
  Host ns1.examplens.com not found: 3(NXDOMAIN)

• The domain can be resolved if a query is performed directly to the IP address of the server. In this example, the server’s IP is 203.0.113.2:

  # host example.com 203.0.113.2
  Using domain server:
  Name: 203.0.113.2
  Address: 203.0.113.2#53
  Aliases:
  example.com has address 203.0.113.2
  example.com mail is handled by 10 mail.example.com.

Cause

Domain’s authoritative NS servers have no “A” DNS records, therefore DNS cannot resolve them to run a query.

Resolution

• If authoritative NS servers (ns1.examplens.com and ns2.examplens.com) are hosted in Plesk:

  1. Log into Plesk
  2. Go to Domain > examplens.com > DNS Settings
  3. Add A records ns1 and ns2 with server’s IP address, as per the Knowledge Base article: How to add a DNS record for a domain in Plesk

• If authoritative NS servers (ns1.examplens.com and ns2.examplens.com) are not hosted on Plesk:

  Contact the domain registrar or DNS provider for assistance to add “A” record on ns1 and ns2 records side.

Additional Information

How to use DNS with a Plesk server