I'm trying to set up MailTrain (a newsletter application) on an Azure VM. I created a resource group with the virtual machine, a virtual network, a network interface, a network security group, a public ip adress and a private DNS zone.
MailTrain expects three URL endpoints which all point to the same IP adress. For testing purposes I would like to create internal endpoints which all point to the VM. I played around with DNS entries in the DNS zone, but it doesn't work as I expected.
The name of the private DNS zone is equal to the DNS name of the VM's public IP adress. The private DNS zone and the VM are linked with the virtual network link and auto registration is enabled. The virtual network contains a default subnet. I created an A entry for "lists" pointing to the VM's internal IP adress and a CNAME entry for "sbox" pointing to the DNS name of the public IP adress. Inbound rules for the ports 80 and 443 were added to the netwwork security group.
The console shows me the following message while running the installation script:
Domain: lists.xxx.cloudapp.azure.com
Type: None
Detail: DNS problem: NXDOMAIN looking up A for
lists.xxx.cloudapp.azure.com - check that
a DNS record exists for this domain
Domain: sbox.xxx.cloudapp.azure.com
Type: None
Detail: DNS problem: NXDOMAIN looking up A for
sbox.xxx.cloudapp.azure.com - check that a
DNS record exists for this domain
Domain: xxx.cloudapp.azure.com
Type: unauthorized
Detail: Invalid response from
https://xxx.cloudapp.azure.com/.well-known/acme->challenge/VIjYMd-Uic_T2lQBl4vSyy9Va46-yVxmTA8SSE3f8J8
[xxx.xxx.xxx]: "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML
2.0//EN\">\n<html><head>\n<title>503 Service
Unavailable</title>\n</head><body>\n<h1>Service"
Followed that quick start, you just need to create three DNS records in your public domain DNS zone.
Please note that there is public DNS and private DNS in Azure. In this case, I assume you have created a private DNS zone for internal endpoints. To resolve the records of a private DNS zone from your virtual network, you must link the virtual network with the zone. Additionally, you can also enable autoregistration on a virtual network link. If you enable auto registration on a virtual network link, the DNS records for the virtual machines on that virtual network are registered in the private zone. Or, you can manually create an A record to map to your VM's private IP address in the zone and create other CNAME records to map to the other internal endpoints.
As a best practice, do not use a .local domain for your private DNS zone. Not all operating systems support this.
In addition, you need to add inbound ports 80, 443 in your network security group that associated with the Azure VM subnet or NIC.
Update
For an internal test, you can use a private DNS zone because the DNS records in a private Zone can only be resolved in a virtual network it can not be resolved over the Internet, you could select the local installation in this scenario.
For example, I create a private DNS zone named contoso.com,
After local install, you can access the website via the trusted endpoint http://localhost:3000, then you should access the other endpoints in the VNet instead of access external.
However, if you want to use it for public access, you could select to install a public website secured by SSL. In this case, you need to purchase a domain and add the related DNS records to the DNS zone in the respective DNS provider. Azure DNS zone supports host your public domain zones in Azure.
Related
Hi currently I have setup a VNET.
Inside this vnet I made a VM and I added an App-Service in the subnet with an private-endpoint.
The private-endpoint of the App-Service is also automatically added to a privatelink DNS zone. (Azure created this automatically for me) It also points correctly to the right internal ip address.
Now from within my VM I try to access my AppService using curl and using the created .privatelink.azurewebsites.net link to the AppService. But it keeps returning 404.
How is this possible. My knowledge of DNS is limited.
If I do a NSLOOKUP inside the VM, it nicely resolves the privatelink DNS Name and finds the private-endpoint ip address
What am I missing?
Update
When I keep using the original azurewebsites.net xxxxxxx.azurewebsites.net (not the privatelink) URL I can access the appservice from within the VNET.
If I am on the VM, and I do a lookup of the original URL I get this.
Non-authoritative answer:
xxxxxxxxx.azurewebsites.net canonical name = xxxxxxxxx.privatelink.azurewebsites.net.
Name: xxxxxxxx.privatelink.azurewebsites.net
Address: 10.1.1.4
So there is some magic behind the scenes?
When you create a public Azure App Service "xxxxxxxxx", beside provisioning the app service environment also a DNS entry for this new service will be created in one of Microsoft's authoritative DNS servers (they are usually named like ns1-xxx.azure-dns.com) ultimately pointing to the public IP address of the server where your your app service is hosted.
If you add a private endpoint for your app service, the DNS entry in these servers won't be removed. Instead what's happening is that internet access to your web app is cut off using firewall rules.
This means if you type in "xxxxxxxxxx.azurewebsites.net" in your browser outside the VNet, a DNS query is sent and the public IP address of the server is returned. Your browser sends a HTTP query to that IP address but will get a HTTP status code 403 indicating that public traffic is blocked.
Inside your VNet the situation is different. As you described you got a private DNS zone "privatelink.azurewebsites.net" which is linked to the VNet (you can see that in the "Virtual network links" section)
If you now type "xxxxxxxxxx.azurewebsites.net" in a browser in your VM which is placed in the same VNet as xxxxxxxxxx.azurewebsites.net, the DNS server associated with the network adapters (by default accessible in your VM through 168.63.129.16) will use the entries placed in the private DNS zones. If a zone named "privatelink.azurewebsites.net" exists, all queries for the domain "azurewebsites.net" will be resolved using this private DNS zone. For example, if there is an A record entry for "xxxxxxxxxx" for 172.16.0.5...
...this is exactly the IP you'll get when you resolve xxxxxxxxxx.azurewebsites.net in your Azure VM:
C:\Users\vm>nslookup xxxxxxxxxx.azurewebsites.net
Server: UnKnown
Address: 168.63.129.16
Non-authoritative answer:
Name: xxxxxxxxxx.privatelink.azurewebsites.net
Address: 172.16.0.5
Aliases: xxxxxxxxxx.azurewebsites.net
If you delete your private DNS zone, the DNS server will resolve back to ns1-xxx.azure-dns.com which in turn will give you the public IP of the service:
C:\Users\vm>nslookup xxxxxxxxxx.azurewebsites.net
Server: UnKnown
Address: 168.63.129.16
Non-authoritative answer:
Name: waws-prod-am2-459-d21a.westeurope.cloudapp.azure.com
Address: 20.50.2.66
But since the app service still has firewall rules applied that block all traffic coming from outside the VNet, you will get a HTTP status code of 403 if you try to access the service over a browser.
See also: https://learn.microsoft.com/en-us/azure/app-service/networking/private-endpoint#conceptual-overview
i created VM behide Azure Load Balancer. i want to use custom domain to Load Balance Public IP. for example i want to access url like 'xx.mvg.com' instead Load Balance Public IP from internet. how i can do it?
i tried to did followed reference link 'https://learn.microsoft.com/en-us/azure/dns/dns-custom-domain' but still not working.
Please recommend how to register my domain name i wish, i want map my domain name to my application running on VM behide Azure Load Balancer.
and Azure have service about internet domain registrar?
about your last question - no, Azure have only Azure DNS, which is not a domain registrar, but a DNS as a service.
Easiest way to achieve what you want - assign a dns name to a public ip (called dns label here) and create a CNAME record in your DNS for that DNS name. or just straight up create a A record in your DNS and point it to your public ip.
I have resource group on azure containing virtual machine and kubernetes and load balancer and public ip address and etc.
I can access to my kubernetes app with direct public ip or public ip dns name. But problem is that i can't get azure custom dns (dns zone) working for my public ip. e.g. myapp.com
I have tried to assign public ip address in dns zone but not getting custom dns name working for my app.
2 options:
1. A record that points to public ip address explicitly
2. CNAME record that points to azure "internal" dns name
From the description it looks like you haven't updated the name server settings of your domain (e.g. myapp.com) to use Azure DNS's name servers (where you have created a zone for that domain name) for query resolutions.
The article linked below has instructions on how to do it. Please let us know if this answers your question.
https://learn.microsoft.com/en-us/azure/dns/dns-delegate-domain-azure-dns
I have an azure network set up with the default Azure DNS.
All the VMs are ubuntu.
When I try to access another VM on the network via the public DNS name it resolves to the public IP.
How do I make it resolve to the internal IP when I request it from the virtual network (and obviously still resolve to the public IP when requested externally).
I'm interested in cli answers as well as configurations through the portal.
Azure DNS for IaaS and PaaS solutions
Please see this article for more information on Azure's own DNS service associated with virtual networks. In short
When role instances and VMs hosted in Azure need to resolve domain
names to internal IP addresses, they can use one of two methods:
Azure-provided name resolution
Name resolution that uses your own DNS server (which might forward queries to the Azure-provided DNS servers)
The type of name resolution you use depends on how your VMs and role
instances need to communicate with each other.
Azure DNS Private Zones (in preview)
There's also a relatively new service called, Azure DNS Private Zones that allow you to set up a private DNS service to be used with, for example virtual networks.
This service allows you to set up a private domain and private IPs for your machines. See this page for more information and some common usage scenarios.
Also, see this this feature suggestion:
Enable split DNS for providing both public and internal name resolution to VMs in the VNET
Is there a way to point an Azure NIC to the records one created in an Azure DNS zone?
At present Azure DNS doesn't support private DNS zones, i.e. those only available to your vnet. Also, the DNS servers specified in the "Add DNS server" box needs to be a recursive resolver, Azure DNS is an Authoritative DNS service, i.e. it will only serve answers for the zones it hosts.
We can't add Azure DNS zone to NIC custom DNS. The custom DNS required IP address, we can add the DNS server IP address to it.
For example, we can add 8.8.8.8 to it, also we can add local DNS server IP address to it(need VPN). Or create a Azure windows VM and install DNS role on it, and add this VM ip address to it.
If you want to use Azure DNS zone to manage your records, we can map your own domain name to DNS zone, and add name servers to your domain name(add this by domain name registrar manage webpage).
The following image shows an example DNS query about Azure DNS zone:
If you want to add record to DNS zone, and you want to map your 3rd party domain name map to Azure DNS zone, we can follow those steps in that answer.
Note:
Keep in mind Azure DNS is not the domain registrar, we should buy domain name from domain registrar(like godaddy, register.com).
Update:
If you just want to use domain name in your virtual network, there is no need to buy a domain, we can use AAD DS in our virtual network. Or we can deploy a VM and install DC on it, work as on-prem.
By the way, in the same virtual network, we can ping VM's name by default.