DNS Checker - DNS Check Propagation Tool

DNS Propagation Checker - How to Check DNS Propagation Globally

DNS Checker provides a free online DNS Checker tool to check DNS propagation globally. The tool checks the DNS data of any hostname or domain from the worldwide DNS servers.

DNS Checker has a list of more than 100 global DNS servers to make global DNS checks easy. You can add the custom DNS server and perform the DNS check based on IP, Continent, and Country.

Our global DNS test tool collects, parses, and displays the DNS propagation results on a map to make results easier to understand. The green tick shows that the requested DNS record is available in the DNS server, and the cross shows that they are not. The green tick also means that the DNS record matches the updated value that the user has set in the expected value field, and the cross shows that the value does not match the expected or updated value (that user expects it to be). Individual DNS record propagation lookup on global DNS servers can be seen by selecting each DNS record.

The most famous DNS record types are

• A record: contains the IPv4 address info of the hostname.
• AAAA record: contains the IPv6 address info of the hostname.
• CNAME record: also known as alias record. It points the sub-domain to its domain, like pointing www.dnschecker.org to dnschecker.org
• MX record: contains the info where the domain's email should be routed to and mail servers priority.
• NS record: contains the info about the authoritative nameservers of a domain.
• TXT record: is commonly used for other DNS records configurations like SPF, DKIM, or DMARC records.

What is DNS propagation?

DNS propagation is the time DNS changes take to be updated across the internet over the globe. It can take up to 48 hours to propagate worldwide. You can check your DNS propagation results from DNS Propagation Checker.

What is DNS resolution?

DNS resolution translates the domain name into its server IP address. You need a site's IP address to know where it’s on the Internet. A website could have IPv4 or IPv6 addresses or both. The IPv4 address comes as A record, and the IPv6 address is in AAAA record.

How do DNS records propagate?

When you update your DNS records, the changes may take up to 48 hours to take effect. During this period, ISPs worldwide update their DNS cache with new DNS information for your domain.

However, due to different DNS cache levels, some visitors might be directed to the old server’s IP for some time after the DNS records change and until it finishes propagating completely worldwide. However, most visitors see updated DNS records shortly after they change. You can look up A, AAAA, CNAME, and additional DNS records lookup from the Dig (DNS lookup) tool.

Why DNS propagation takes time?

Suppose you changed your domain's nameservers and requested to open your domain on the web browser. Your request will not go to the hosting directly.

Each ISP node first checks its DNS cache, whether it has the DNS information for that domain. If it is not there, it will look it up by fetching DNS information from the authoritative DNS server of the domain to serve the user’s request, and it saves it for future use to speed up the DNS lookup process.

Thus, the new nameservers will not propagate instantly - ISPs have different cache refreshing levels, so some will still have the old DNS information in their cache.

But if, after that time interval, still, your new DNS changes are not reflecting, then you go for a DNS health check to ensure that your DNS changes are up to the mark and are following the standards. Or you can go for flushing your DNS cache.

Why is DNS not propagating?

The ISPs across the world have different caching levels. The DNS client or the server may cache the information of the DNS records in its DNS cache. That information is temporarily cached, and DNS servers will go for the updated DNS information when TTL (Time to Live) expires.

What is a domain name system, and what type of DNS servers are involved in the DNS check process?

Domain Name System (DNS) is a hierarchical decentralized system that maps domain names to IP addresses. It is the internet's equivalent of a phone book, mapping human-readable domain names to IP addresses.

There are three types of DNS servers involved in the DNS resolution process:

1. Recursive DNS server (DNS resolver): These servers are the first in the DNS check process. Receive DNS queries from clients and resolve the human-readable domain name to an IP address. That server tracks the IP address for the searched domain or hostname.
2. Root DNS servers: These servers are at the top of the DNS hierarchy and provide a list of top-level domain (TLD) servers to resolvers.
3. Authoritative DNS servers: These servers are the last stop in the DNS resolution process. The authoritative nameservers for the searched domain hold the actual DNS records and respond to queries with the correct IP addresses.

How does the DNS process work?

Suppose you request to open the URL https://xyz.com in your web browser's bar.

1. Your browser sends a DNS query to a DNS resolver (recursive Server), usually provided by your Internet Service Provider (ISP).
2. The recursive resolver checks its cache to see if it already has the requested DNS information for the domain name. If it does, it returns to your computer, and the process ends.
3. If the recursive resolver doesn't have the DNS information in its cache, it sends a query to the root DNS servers. These servers maintain a database of all the top-level domain names, such as .com, .org, .net, etc.
4. The recursive resolver then contacts the root DNS servers that respond to the query with the IP of appropriate TLD (Top-Level Domain) DNS servers.
5. The TLD DNS servers respond to the query by referring to the authoritative DNS servers for the domain name. These servers are responsible for maintaining the DNS records for the domain.
6. The authoritative DNS servers respond to the query with the requested DNS records for the domain name.
7. The DNS resolver caches the updated/latest fetched DNS records and returns them to your computer, which can now be used for whatever purpose those records were requested.

Which are the best DNS servers?

Some of the best Global DNS servers are

1. Google Public DNS:
   • IPv4:
     • Primary: 8.8.8.8
     • Secondary: 8.8.4.4
   • IPv6:
     • Primary: 2001:4860:4860::8888
     • Secondary: 2001:4860:4860::8844
2. OpenDNS:
   • IPv4:
     • Primary: 208.67.222.222
     • Secondary: 208.67.220.220
   • IPv6:
     • Primary: 2620:119:35::35
     • Secondary: 2620:119:53::53
3. Quad9 (Malware Blocking Enabled):
   • IPv4:
     • Primary: 9.9.9.9
     • Secondary: 149.112.112.112
   • IPv6:
     • Primary: 2620:fe::fe
     • Secondary: 2620:fe::9
4. DNS.Watch:
   • IPv4:
     • Primary: 84.200.69.80
     • Secondary: 84.200.70.40
   • IPv6:
     • Primary: 2001:1608:10:25::1c04:b12f
     • Secondary: 2001:1608:10:25::9249:d69b
5. Comodo Secure DNS:
   • IPv4:
     • Primary: 8.26.56.26
     • Secondary: 8.20.247.20
6. Cloudflare:
   • IPv4:
     • Primary: 1.1.1.1
     • Secondary: 1.0.0.1
   • IPv6:
     • Primary: 2606:4700:4700::1111
     • Secondary: 2606:4700:4700::1001

        

Public DNS Servers by country provide a complete list of all DNS servers, including the world's best IPv4 and IPv6 public DNS servers.

FAQs

What will happen if the domain name does not exist?

The DNS server will return a name error, also known as an NXDomain response (for a non-existent domain), to symbolize that the query's domain name does not exist.

What is the port used by DNS?

DNS uses both TCP and UDP port 53. However, the most frequently used port for DNS is UDP 53. That is used when the client's computer communicates with the DNS server to resolve the domain name. When using the UDP 53 for DNS, the maximum size of the query packet is 512 bytes.

TCP 53 is used primarily for Zone Transfers and when the query packet exceeds 512 bytes. That is true when DNSSEC is used, which adds extra overhead to the DNS query packet. You can test all the server ports using a port scanner online.

What is DNS failure?

DNS failure means that the DNS server cannot convert the domain name into an IP address in a TCP/IP network. That failure may occur within the company's private network or the internet.