Troubleshooting guide for domain resolution failures, explaining common causes and solutions for DNS-related connectivity issues.
When a domain fails to resolve, it means that DNS queries for the domain are not returning the expected IP addresses. This can happen for several reasons, including incomplete propagation of DNS changes, incorrect delegation at the registrar, or conflicting DNS configurations across multiple providers. Understanding the relationship between your domain registrar, authoritative name servers, and DNS records is key.
After updating your domain’s nameservers or DNS records, it can take 24–48 hours for the changes to propagate globally. During this period, some users may still receive outdated DNS information, causing the domain to appear unresolvable. To check if the changes have propagated, you can use command-line tools such as:
$ dig NS yourdomain.com +short
If your domain is correctly configured for Vultr, the expected output is:
ns1.vultr.com.
ns2.vultr.com.This confirms that DNS queries are reaching the Vultr authoritative nameservers.
If your domain is not pointing to Vultr’s authoritative name servers (ns1.vultr.com and ns2.vultr.com), DNS queries will not reach your Vultr zone, and the domain will fail to resolve. To address this, log in to your domain registrar and update the delegation so that your domain uses only Vultr’s nameservers. Proper delegation ensures that all DNS queries are directed to the correct zone where your records are defined.
Using multiple DNS providers for the same domain can lead to inconsistent resolution. For instance, if an A record exists on Vultr pointing to one IP while another provider points to a different IP, some users may reach one server while others reach another. To resolve such conflicts, manage all DNS records exclusively within Vultr DNS and ensure that your domain is delegated only to Vultr’s nameservers. This centralizes control and prevents mismatched records from causing resolution issues.
Some registrars may impose temporary locks or other restrictions that prevent DNS updates from taking effect immediately. If your domain fails to resolve despite correct configuration, you can check the registrar status using:
$ whois yourdomain.com
This lets you verify that the domain is not under a transfer lock or other restriction that could hinder DNS changes. Ensuring the registrar permits updates will help DNS changes propagate correctly.