Connecting Records from Different Zones

Question

Connecting Records from Different Zones

Soar 116

I know that if I have ServerName.DomainName1.com with IP 192.168.0.X, I should create an A record. And if I have Alias.DomainName1.com for the same server, I should create a CName record pointing at ServerName.DomainName1.com.

But that is probably true because both belong to the same zone.

How about if I have ServerName.DomainName1.com and Alias.DomainName2.com? Should I create an A or CName record for Alias?

Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T19:05:34+00:00
Hi Soar,

About your question you will need to create 2 DNS zone like:

az network dns zone create --name DomainName1.com --resource-group myresourcegroup az network dns zone create --name DomainName2.com --resource-group myresourcegroup

After have your dns zone you need to create the dns record:

az network dns record-set a add-record --ipv4-address 192.168.0.X --record-set-name ServerName --resource-group myresourcegroup --zone-name DomainName1.com az network dns record-set a add-record --ipv4-address 192.168.0.Y --record-set-name Alias --resource-group myresourcegroup --zone-name DomainName2.com

More information about Dns record:

https://learn.microsoft.com/en-us/azure/dns/dns-zones-records

https://learn.microsoft.com/en-us/azure/dns/dns-troubleshoot To test your resolution you can use nslookup tool and point to the NS server names of this DNS zone (Will take some time to propagete after dns zone creation)

Let me know if this solve your question,

Cheers,

Luis Arias

If the information helped address your question, please Accept the answer.
Soar 116 Reputation points

2023-11-17T21:11:56.0866667+00:00
Thank you for your reply!

My DNS is not Azure. But that was the only option to select, and I thought it should be the same.

Both zones are already available and have so many records in them. I am not asking about how to create a zone.

I don't understand why you used 2 IP addresses. It's a single server with a single network interface.

My question isn't about how create a record either. My question is about weather I should create an A record or CName record for the alias. Because the original A record of the server's host name is in one zone, and the alias will be in the other zone.
Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T21:45:39.1333333+00:00

Hey Soar, I got you now, In your case, if the IP address of the server is not going to change frequently, you can use an A record in both zones. This way, you directly associate your domains with the IP address of the server.

However, if the IP address of the server might change, it would be better to use a CNAME record for the alias in the other zone. This way, even if the IP address of the server changes, you only need to update the A record in the original zone, and the CNAME record in the other zone will still correctly point to the server.

Remember, CNAME records can cause additional DNS lookup overhead because the DNS resolver needs to resolve both the CNAME record and the A record it points to. So, if performance is a concern, and the IP address is not expected to change, A records might be a better choice.

Let me know if this help you.
Soar 116 Reputation points

2023-11-17T22:37:27.4033333+00:00

I know why we would use CNames. I am only asking because the alias doesn't belong to the same zone as the original A record of the host name.

So, are you saying that the best practice is still to create a CName record when the performance isn't an issue?

If yes, kindly put that in a new answer so I can accept it. Because your previous answer was a misunderstanding.
Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T22:57:07.6333333+00:00

Hi Soar,

If domain2 is an alias for domain1 and they are pointing to the same server (server1), using a **CNAME**record for domain2 pointing to domain1 would be easy. This way, if the IP address of the server changes, you only need to update the A record for domain1, and domain2 will automatically follow due to the **CNAME**record.

However, the best practice is to use the record type that best fits your needs and the structure of your environment. CNAME records can cause additional DNS lookup overhead and DNS configuration can greatly impact the performance and reliability of your services, so it’s important to plan and test your setup carefully.

Here Additional information than can be helpfull:
https://activedirectorypro.com/dns-best-practices/

https://www.cloudflare.com/learning/dns/dns-records/dns-cname-record/

Regards,

Luis
Soar 116 Reputation points

2023-11-18T05:02:23.21+00:00

I don't know whether one domain name is an alias for another domain name. All I said is that I have a server which has a host name (just like any other computer in the world), and also has an alias.

And I honestly don't like it when you expand your posts by telling me information I already know, and then keep repeating yourself.

I have a powerful server. And I know for what purpose we use CName records. And I know that when I have an alias for a server (not for a domain) I should create a CName record, because the server will move from one cloud to another from time to time, and because some servers have multiple aliases.

The only reason I am asking this question is that this time, I need to put a record for an alias in other than the zone where the host name is recorded. That's it.

So if you think that the other information you're providing helps me understand why I should create an A or CName record, explain that the relationship between the two topics, and don't repeat unless you see that I don't understand. Otherwise, just kindly focus on the topic. See how big this thread has become.

Your answer

Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T19:05:34+00:00

Hi Soar,

About your question you will need to create 2 DNS zone like:

az network dns zone create --name DomainName1.com --resource-group myresourcegroup az network dns zone create --name DomainName2.com --resource-group myresourcegroup

After have your dns zone you need to create the dns record:

az network dns record-set a add-record --ipv4-address 192.168.0.X --record-set-name ServerName --resource-group myresourcegroup --zone-name DomainName1.com az network dns record-set a add-record --ipv4-address 192.168.0.Y --record-set-name Alias --resource-group myresourcegroup --zone-name DomainName2.com

More information about Dns record:

https://learn.microsoft.com/en-us/azure/dns/dns-zones-records

https://learn.microsoft.com/en-us/azure/dns/dns-troubleshoot To test your resolution you can use nslookup tool and point to the NS server names of this DNS zone (Will take some time to propagete after dns zone creation)

Let me know if this solve your question,

Cheers,

Luis Arias

If the information helped address your question, please Accept the answer.
Soar 116 Reputation points

2023-11-17T21:11:56.0866667+00:00

Thank you for your reply!

My DNS is not Azure. But that was the only option to select, and I thought it should be the same.

Both zones are already available and have so many records in them. I am not asking about how to create a zone.

I don't understand why you used 2 IP addresses. It's a single server with a single network interface.

My question isn't about how create a record either. My question is about weather I should create an A record or CName record for the alias. Because the original A record of the server's host name is in one zone, and the alias will be in the other zone.
Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T21:45:39.1333333+00:00

Hey Soar, I got you now, In your case, if the IP address of the server is not going to change frequently, you can use an A record in both zones. This way, you directly associate your domains with the IP address of the server.

However, if the IP address of the server might change, it would be better to use a CNAME record for the alias in the other zone. This way, even if the IP address of the server changes, you only need to update the A record in the original zone, and the CNAME record in the other zone will still correctly point to the server.

Remember, CNAME records can cause additional DNS lookup overhead because the DNS resolver needs to resolve both the CNAME record and the A record it points to. So, if performance is a concern, and the IP address is not expected to change, A records might be a better choice.

Let me know if this help you.
Soar 116 Reputation points

2023-11-17T22:37:27.4033333+00:00

I know why we would use CNames. I am only asking because the alias doesn't belong to the same zone as the original A record of the host name.

So, are you saying that the best practice is still to create a CName record when the performance isn't an issue?

If yes, kindly put that in a new answer so I can accept it. Because your previous answer was a misunderstanding.
Luis Arias 8,621 Reputation points Volunteer Moderator

2023-11-17T22:57:07.6333333+00:00

Hi Soar,

If domain2 is an alias for domain1 and they are pointing to the same server (server1), using a **CNAME**record for domain2 pointing to domain1 would be easy. This way, if the IP address of the server changes, you only need to update the A record for domain1, and domain2 will automatically follow due to the **CNAME**record.

However, the best practice is to use the record type that best fits your needs and the structure of your environment. CNAME records can cause additional DNS lookup overhead and DNS configuration can greatly impact the performance and reliability of your services, so it’s important to plan and test your setup carefully.

Here Additional information than can be helpfull:
https://activedirectorypro.com/dns-best-practices/

https://www.cloudflare.com/learning/dns/dns-records/dns-cname-record/

Regards,

Luis
Soar 116 Reputation points

2023-11-18T05:02:23.21+00:00

I don't know whether one domain name is an alias for another domain name. All I said is that I have a server which has a host name (just like any other computer in the world), and also has an alias.

And I honestly don't like it when you expand your posts by telling me information I already know, and then keep repeating yourself.

I have a powerful server. And I know for what purpose we use CName records. And I know that when I have an alias for a server (not for a domain) I should create a CName record, because the server will move from one cloud to another from time to time, and because some servers have multiple aliases.

The only reason I am asking this question is that this time, I need to put a record for an alias in other than the zone where the host name is recorded. That's it.

So if you think that the other information you're providing helps me understand why I should create an A or CName record, explain that the relationship between the two topics, and don't repeat unless you see that I don't understand. Otherwise, just kindly focus on the topic. See how big this thread has become.

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Connecting Records from Different Zones

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