Tag: A record

CNAME record explained

CNAME record

The CNAME record is one of the first DNS records that you will read about when you are starting with DNS management. It has a very important task to do, showing the true domain name for the subdomains, making it really an essential DNS record. It saves time and makes it easier to manage the DNS.

CNAME explained completely

There are two parts in the CNAME’s name. C stands for canonical, and it wants to show which is the true domain name for the one that you are trying to resolve. The NAME is obvious. It stands for name, as in hostname.

The purpose of the CNAME record is to point one hostname to another. You can point different subdomains to the domain name. That way, you don’t need to add any other records for the subdomain because it will automatically redirect to the domain name.

If you have just a single DNS record for each subdomain, you will have far fewer DNS records, and the administration of your domain will be a lot easier.

CNAME records can be used to point:

www.domain.com to domain.com

blog.domain.com to domain.com

mail.domain.com to domain.com

newyork.domain.com to domain.com

Because of the way the CNAME record works, if the host (subdomain) already has other DNS records like A, MX, etc., you can’t create a CNAME record. And if you first create a CNAME record in the zone, you can’t create any other type of record in that zone.

Inside a CNAME record, you will see:

Host – the name of the subdomain that you want to point to the main domain name.

Type – CNAME.

Points to – the domain name. All of the CNAME records will point to this one.

TTL – time to live for that DNS record.

How to lookup a CNAME record?

If you are on Windows, the easiest and the safest way to check a CNAME record is to use the nslookup command. Go to the cmd (Command Prompt). Type “nslookup”, and press Enter. Now type “set type=cname”, and press Enter. The last pass is to write down the hostname, which you want to check. See this example, “mail.bing.com” and you will see the canonical name “star-bing-com.a-0001.a-msedge.net”.

If you are using Linux, go for the dig command. Open the Terminal and type “dig cname mail.bing.com,” and you will see the same “star-bing-com.a-0001.a-msedge.net” plus additional information. Dig command has very rich answers.

CNAME vs ALIAS

There is a newer type of DNS record called ALIAS that also points one hostname to another. It can do almost all that the CNAME can, but it can coexist with other records and can be added to the apex zone.

CNAME vs A record

The CNAME and the A records are very different. CNAME point one hostname to another while the A record points the domain name to an IP address. Also, if you want to resolve a domain, and first you get a CNAME, then you will need the A record too. So, the CNAME will take 2 queries instead of 1.

If you are interested in DNS records, check our article about the DNS CAA record!

DNS propagation explained

DNS propagation

Imagine this situation. You have finally decided to truly manage your DNS. You have selected a DNS service provider, you have created master and secondary zones, and you have added all the DNS records that you will need. You spend a lot of time and effort. And after everything is ready, you want to check and… there are no changes! Don’t worry. The DNS propagation takes time.

What is DNS propagation? 

It is a process to update the changes that you make in your DNS. After editing or creating new DNS records, they are saved in the authoritative DNS nameserver. That is ok, but what about all the rest of the DNS name servers? The cache memory of the recursive DNS servers will still keep the older versions of the DNS records based on their TTL value.
The DNS propagation is the time it will take to propagate, to update the changes to all of the recursive name servers.

Frequently asked questions about DNS propagation

Do you have any doubts about the DNS propagation, we hope you can find your answer here:

Could we make the DNS propagation faster?

Of course, we can, but there is a catch. Boosting the speed depends on the TTL value of the DNS records, so lowering the TTL value of each of the DNS records will indeed guarantee faster DNS propagation. The problem is that you might not want to have DNS records with low value. It will stress more your DNS servers, updating them too often.
We don’t need all of our DNS records to update all the time.
It is better to keep the records’ TTL values at their normal level. Plus, editing all of them will take a lot of time.

Can you check if the DNS propagation is ready?

Of course, we can, and this time there is no problem. You need to see if the IP address for a domain name has changed. This will indicate that the A or AAAA records are updated already.
We will show you different ways depending on your OS.

*Change yourdomainname.com with your actual domain name.

Linux or macOS

Open the Terminal, and we will use one of the built-in commands called the Dig command.

dig yourdomainname.com

You can use the host command too, whatever you prefer.

Windows OS
The Terminal alternative in Windows is the Command Prompt. Inside it, we will use the NSlookup command.

nslookup yourdomainname.com

How long can the DNS propagation take?

It can take a long time. Depending on when the recursive DNS servers updated themselves and the TTL values of the DNS records, it can take as much as 72 hours.

Conclusion

Waiting for the DNS propagation to occur is a time-consuming process that we could not fully predict. This is the situation, and there is little we can do, so just be patient, and in less than 72 hours, the update will happen.
Patience is the key here!

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