Azure - Can't create load balancer for the ScaleSet

Question

I created a Scale Set (using a template) with an existing virtual network.
This existing virtual network has already a Load Balancer (with a public IP) with specific VMs.

Now, I can't connect to the VMs in the scale set, There's no option to add the scale set to the Load Balancer or to add the scale set's VMs to the Load Balancer. Creating a new Load Balancer doesn't help.
It seems that the only option for adding a backend pool is using an availability set or a single VM (which is not in the Scale Set).

Is there any way to solve this? to somehow add the Scale Set to the Load Balancer or to connect to it?

The goal was to create the scale set to be in the existing Load Balancer (in the network with the other VMs), but unfortunately it didn't work.

Answer 1

It is not posible to add vms in different availability sets to the same lb. VMSS has its own availability set (by desing). so this is not possible.

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/ccf69a9c-0a6a-47bc-afca-561cf66cdebd/multiple-availability-sets-on-single-load-balancer?forum=WAVirtualMachinesVirtualNetwork

You can work around by creating vm in the network that will act as a load balancer, but that's obviously not a PAAS solution

Answer 2

The goal was to create the scale set to be in the existing Load Balancer (in the network with the other VMs), but unfortunately it didn't work.

It is not possible and no need. Please refer to this official document. Azure VMSS instances are behind a load balancer. Also VMSS's intance could not add to a existing load balancer.

Now, I can't connect to the VMs in the scale set.

Do you create inbound NAT rules for your instance? Also, you could create a jump VM in the same VNet to login one instance. See this question.

If you could not login your VM from a jump VM, it is not a VMSS issue. You should check your instance. If you don't do any change for your instances. You could create a ticket to Azure to solve this issue.