Azure-docs: VM scale set does not work with internal standard sku Azure load balancer backend pool

[Qq20180503]

In a basic load balancer, we could select VM, VM scale set, and availability set as the backend pool on the Azure portal. Yet in Standard LB not. even though it is mentioned in the documentation it supports it. https://docs.microsoft.com/en-us/azure/load-balancer/load-balancer-standard-overview#why-use-standard-load-balancer

Standard Load balancer
Backend pool endpoints
Any virtual machine in a single virtual network, including blend of virtual machines, availability sets, virtual machine scale sets.

Currently, we can associate a public facing load balancer with VM scale set when creating a scale set on the Azure portal. But if we create an internal standard load balancer and a scale set separately. We could not select this scale set as backend pool. Is this an expected action? How to add the VM scale set as the backend for an internal standard load balancer?

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Document Details

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• ID: 09325ff2-5a0a-0aff-e3cb-d1c0585a6842
• Version Independent ID: f370d680-5d1d-99a9-e350-7d9551d24ce6
• Content: What is Azure Standard Load Balancer?
• Content Source: articles/load-balancer/load-balancer-standard-overview.md
• Service: load-balancer
• GitHub Login: @KumudD
• Microsoft Alias: kumud

[SubhashVasarapu-MSFT]

@Qq20180503 Thanks for the feedback! We are currently investigating and will update you shortly.

[Qq20180503]

@SubhashVasarapu-MSFT May I know if there is any update on this question?

[raleonardo]

Hi,
What I experience is that I can associate the vmss as a backend for the load balancer, save it, but then the deployment completes but then the backend pool exists but is unassociated.


Then if I try to reassociate it to the VMSS, I save it and then the deployment fails.

[SubhashVasarapu-MSFT]

@Qq20180503 Thanks for the feedback! I have assigned the issue to the content author to investigate on this.

[christiankuhtz]

@Qq20180503 does your scaleset have public IP's associated with it as instance-level public IP's for the VMSS instances? If so, they need to be standard SKU as well. You can achieve this by creating the LB first and then creating the VMSS with a reference to the LB at create time, which will cause the public IP SKU to match the lb sku.

[SubhashVasarapu-MSFT]

@Qq20180503 We will now proceed to close this thread. If there are further questions regarding this matter, please tag me in your reply. We will gladly continue the discussion and we will reopen the issue.

[Qq20180503]

@SubhashVasarapu-MSFT and @christiankuhtz. My scale set has no public IP address and no instance-level public IP address as well. I create the standard LB with a private IP in a VNet first, then create a vmss with the option"none" in the Azure portal, then I still could not add the vmss in the backend of LB. It seems that the public standard LB support vmss, but internal standard LB does not?

[SubhashVasarapu-MSFT]

@Qq20180503 Thanks for bringing this to our notice. We are investigating on this issue and will update you as soon as possible.

[SubhashVasarapu-MSFT]

@Qq20180503 , This requires a deeper investigation, so if you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support. In this case, could you send an email to AzCommunity[at]Microsoft[dot]com referencing this thread and your subscription id.

Thank you for your cooperation on this matter and look forward to your reply.

We will now proceed to close this thread.

[orsharon7]

Hello,

any updates on this thread?
I have just tried to work with VMSS + Standatd LB:

• Attaching existing Std-LB with VMSS is not possible.
• Only creating the Std-LB via the VMSS creation is possible.

[andremarques023]

I'm facing the same issue. Any ETA on this?

[SubhashVasarapu-MSFT]

@andremarques023 , There is planned work item where team is working on it to accomplish this by end of this september.

[Tomer-GRTH]

Hi, any news on the ETA?

[Sparkle-Team]

I am facing this same issue, think one should be able to attach internal lb with scale set.

[christiankuhtz]

@anavinahar fyi