Azure Portal IP-configuration cannot modify DNS-Name of a VM - azure

Question

It is only a few days that I can no longer modify the DNS-name of a new or existing VM on the portal IP-configuration page. A 100% certain that this worked before.
The information says:
Diese öffentliche IP-Adresse kann nicht aktualisiert werden, da sie der IP-Konfiguration „ipconfig1“ in Netzwerkschnittstelle zugeordnet ist.
which is:
This public IP address cannot be updated, because it is assigned to the IP configuration "ipconfig1" in network interface
Anyone an idea why this came up and how to add/change a DNS-Name to a VM now?
Thanks a lot
Urs

Answer 1

The error message "This public IP address can't be updated because it is associated to the IP configuration 'ipconfig1', in the network interface 'nic-name'" is expected behavior with an update to the Azure Portal experience. When you deploy Public IP with Standard SKU, you will be able to modify DNS name post association to NIC. But when you deploy Public IP with Basic SKU, the above mentioned error/warning pops up where you need to disassociate the Public IP to change or add DNS name.
Below are the steps you need to follow to modify the DNS name of your VM:
Select the name of the network interface mentioned in the warning (e.g.,web-vm1234)
Select NIC name
In the Network interface resource, select the IP configurations tab, and then in the list of IP configurations, select ipconfig1.
Select IP config
In the IP configuration, under the Public IP address settings select Disassociate, and then select Save.
Disassociate Public IP
Reference : https://learn.microsoft.com/en-us/azure/virtual-network/remove-public-ip-address-vm
In a new browser tab (leaving the previous tab sitting on the IP configuration tab), navigate to the Azure Portal.
In the Azure Portal, search for and then navigate to the associated public IP address resource.
In the Public IP resource, select the Configuration tab, enter the desired DNS name in lowercase as the DNS name label, and then select Save.
Modify DNS label
Note: Make sure you get the green tick next to your DNS name label. If not, this means the name you have entered is not available. Try adding a number or changing it in some other way to make it unique.
Close the browser tab with the Public IP address, and return to the browser tab you were just on with the ip configuration.
In the ipconfig1 configuration, in the Public IP address section, select Associate and then in the Public IP address list, select the IP address. Finally, select Save.
Associate Public IP
Navigate back to your Virtual Machine and do a refresh. Now you should see the modified DNS name in the VM overview.