Alibaba Cloud DNS:Getting started

Key concepts

How web browsing works: You enter a domain name in a browser. The browser queries DNS for the corresponding IP address, then connects to that IP to load the webpage.

What is DNS and why is it necessary?

DNS translates domain names into IP addresses that computers use to locate services on the network.

How does DNS know the IP address for a domain name?

You configure a DNS record that maps your domain name to its IP address. When someone queries the domain, DNS returns the mapped IP.

Key concepts

Your first task

Configure a DNS record for your domain name to point to an IP address.

Prerequisites

• You have purchased a domain name, such as your-domain.com, from Alibaba Cloud Domain Names and completed domain name identity verification. If your server is in the Chinese mainland, you must also complete website ICP filing.

• You have a public IP address, such as the public IP of an ECS instance.

Quick configuration

1. Visit the Alibaba Cloud DNS - Public Zone page, find your domain name, and click the domain name or Settings.

2. Click Add Record and configure the following parameters.

   Parameter	Sample value	Description
   Record Type	A	Points the domain name to an IPv4 address.
   Hostname	www	If your domain name is your-domain.com, you can access your website at www.your-domain.com when the hostname is set to www.
   Record Value	106.12.XX.XX	Enter your public IP address. Note To test the DNS configuration without an accessible IP address, enter any valid IP address.

   Keep the default values for other parameters.

3. On the Settings page, verify that the new DNS record is available and its Status is Enable.

Verification

New records typically take effect immediately. Updated records take effect after the TTL expires (usually 10 minutes). Verify your configuration using the following methods.

1. Resolution verification

Objective: Verify that DNS resolution returns the correct IP address.

Verification method:

• Use a command-line tool: Run the following commands in your terminal. Replace www.your-domain.com with your domain name and verify the returned IP matches your DNS record.

  # For Windows
  # nslookup <domain_to_query> [<dns_server>]
  nslookup www.your-domain.com ns1.alidns.com # Checks the resolution result from the specified DNS server.
  nslookup www.your-domain.com # Checks the resolution result from the local DNS.
  # For Linux
  # dig @<dns_server> <domain_to_query>
  dig @ns1.alidns.com www.your-domain.com # Checks the resolution result from the specified DNS server.
  dig www.your-domain.com # Checks the resolution result from the local DNS.

  Troubleshooting

  If the result is unexpected, check the following:

  • The DNS record is configured incorrectly. Verify the Hostname and Record Value, and confirm the resolution source is Default.

  • Your local network or ISP may intercept DNS requests. Use the network probe tool to verify the record from external test locations.

2. Website verification

Objective: Confirm that the domain name opens your webpage in a browser. This requires the record value to be the public IP of an accessible web service.

Verification method:

• Browser access: Enter your domain name in a browser, for example, http://www.your-domain.com, and confirm the page loads.

  Troubleshooting

  If the page does not load:

  1. Complete 1. DNS resolution verification first. If resolution works, continue with the checks below.

  2. Verify that the web service is accessible directly via its IP address.

  3. Your browser may default to HTTPS. Try accessing the site with the HTTP protocol: http://www.your-domain.com.

  4. If the service uses a port other than 80, include the port in the URL, for example, http://www.your-domain.com:3000.

  5. Check the domain name status for locks or missing ICP filing.