Add new Public IPs in Azure Firewall

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Add new Public IPs in Azure Firewall

Emil Tsvetkov 55

Hello,

I get this messages when I add new IPs in the Azure Firewall. Can you help to identify the cause of this ?

Thanks

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Answer 1

Jerald Felix 9,015

Hello Emil Tsvetkov,
Greetings!

When adding new Public IPs to Azure Firewall, it's important to follow the correct configuration steps to avoid errors. If you are getting error messages during this process, the likely causes may include:

The Public IP address resource might not be correctly associated with your Azure Firewall.

The IPs being added do not meet the required criteria, such as Standard SKU or proper availability zone settings.

There could be subnet or route configuration issues that prevent the firewall from binding to the new IPs.

Azure Firewall may require a restart or redeployment to recognize changes in Public IP association.

To help you further, please share the exact message you receive when performing the addition. Double-check your resource associations and make sure all dependencies (like subnet and network settings) are correctly configured.

If you continue to face issues, try removing the problematic IP association and re-adding it after refreshing the Azure Portal or using PowerShell/Azure CLI for more detailed error feedback.

Best Regards,

Jerald Felix

Emil Tsvetkov 55 Reputation points

2025-09-23T10:54:33.8566667+00:00

Hi Felix, thanks for replying so fast. I do consider all these items you posted. And all was working perfectly for the last 5 years. I create the new Public IP exactly as the old ones . But it is not available in the drop downlist when associating it with the firewall. There is no error message. I tried to create new IP in the firewall association blade it adds it as new but the Add button doesnot work. No error message only the red cross icon. What am I doing wrong ?
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-09-23T12:17:42.2233333+00:00
Hi @Emil Tsvetkov, thanks for the update. Since you're not seeing any error messages, but the IP isn't appearing in the dropdown and the Add button is unresponsive, here are two steps that might help uncover the issue:

Step 1: Try associating the IP using PowerShell or Azure CLI

This can sometimes reveal more detailed error messages that aren't shown in the portal.

PowerShell Guide: Deploy Azure Firewall with multiple public IP addresses using PowerShell

Azure CLI Reference: az network firewall ip-config | Azure CLI

Step 2: Double-check the following configuration details

Even if everything worked before, it's worth verifying:

SKU: Must be Standard

IP Type: Must be Static

Region & Availability Zone: Should match the firewall

Resource Group & Subscription: Must be the same as the firewall.

Kindly let us know if you need any help doing these checks or if you need further assistance on this issue.

Once we have these checks confirmed we can help find the root cause.
Emil Tsvetkov 55 Reputation points

2025-09-23T12:53:07.3033333+00:00

Thanks a lot .. I will check again all these setting

best Regards

Emil
Emil Tsvetkov 55 Reputation points

2025-09-24T08:22:27.9633333+00:00

HI Thanmayi,

I suspect there is a internal limit of max IPs set per Firewall for region "westeurope". The 250 IPs limit may not be valid in this region. How can I check this? I cannot raise a SUpport Request because I am always routed to autogen suggestions.

Thanks a lot

Emil
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-09-25T13:15:37.1733333+00:00
Hi @Emil Tsvetkov,

The general Azure Firewall limit is 250 public IPs per firewall, regional constraints can impose a lower limit. To check the actual quota for West Europe, you can use the Azure CLI:

az network list-usages --location westeurope --output table

This will show:

CurrentValue – how many public IPs are already in use in the region

Limit – the maximum allowed public IPs

Since Azure Firewall uses standard public IPs, the regional Public IP quota effectively determines how many IPs you can attach to the firewall. If the limit is lower than 250, that would explain why the portal isn’t letting you add more.

If the quota is too low, you can raise a quota increase request.

Kindly let us know if you need any help doing these checks or if you need further assistance on this issue.
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-09-26T15:09:50.72+00:00

Hi @Emil Tsvetkov,

Just checking in to see if you had a chance to see the previous response posted by me. If you have any further questions do let us know.
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-09-29T09:22:05.82+00:00

Hi @Emil Tsvetkov,

Just checking in to see if you had a chance to see the previous response posted by me. If you have any further questions do let us know.
Emil Tsvetkov 55 Reputation points

2025-10-01T07:34:53.7433333+00:00

Hi Thanmayi,

Sorry for replying you today. I was off a couple of days. Thanks for the Azure Cli. I checked and here are the entries. I did not show the exsct values for sec resons.

Which entry must show how many IPs can be added to am Azure Firewall? I cannot find such..

Thanks Best regards

EMil
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-10-02T07:32:57.6633333+00:00
Hi @Emil Tsvetkov,

Thank you for sharing the screenshot and for running the CLI command.

The output of:

az network list-usages --location westeurope --output table

shows regional resource quotas, not firewall-specific limits. There is no direct entry for “Azure Firewall IP configurations” because the command reports usage for resource types like Public IPs, VNets, etc.

For your case:

Look at Public IP Addresses - Standard in the list.

CurrentValue = number of Standard Public IPs currently in use in West Europe.

Limit = maximum allowed Standard Public IPs in West Europe.

Azure Firewall requires Standard SKU Public IPs, so this regional quota determines how many IPs you can allocate overall.

The 250 IP per firewall limit is a service-level constraint and is not shown in this command. It applies globally to the firewall resource itself, regardless of region. You can find this documented here: https://learn.microsoft.com/azure/firewall/firewall-faq#how-many-public-ip-addresses-can-i-associate-with-my-azure-firewall.

If your CurrentValue is close to the Limit, you’ll need to request a quota increase for Standard Public IPs in West Europe. You can do this from the Azure Portal under Subscriptions → Usage + quotas → Request increase.

Kindly let us know if the above helps or if you need further assistance on this issue.
Emil Tsvetkov 55 Reputation points

2025-10-02T09:02:39.56+00:00

Hi ,

It does not look like a quota issue any more.

This is an existing IP configuration.

The dropdownlist is empty although there are IPs to be added.

All my Publc IPs already added to the Firewall are with this

Thanks a lot

Best regards,

Emil
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-10-03T19:29:37.4433333+00:00

Hi @Emil Tsvetkov,

Thank you for sharing the details.

Looks like we need to check some configurations again.

Could you please share the below details over "Private message" option.

Email ID:

Time zone:

Subscription ID:

Tenand ID:
Thanmayi Godithi 1,885 Reputation points Microsoft External Staff Moderator

2025-10-08T11:12:48.77+00:00

Hi @Emil Tsvetkov,

Just checking to see if the issue is resolved for you. Please let us know.

Thanks
Emil Tsvetkov 55 Reputation points

2025-10-08T13:08:07.4633333+00:00

Hi

Thanks a lot for your support. The Issue is now resolved. It could habe been a temporary glitch somekind of..

Thanks a lot again

Best regards,

Emil

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Add new Public IPs in Azure Firewall

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