I am currently investigating various AKS networking options that are available, and while researching CNI with Overlay I found a table comparing Kubenet and CNI with Overlay. documentation.
The part that I do not understand is where does the limit of 1000 nodes come from
The Kubenet is limited by 400 I assume by the number of routers in User-Defined Route Table. However, I am struggling to find the reason for 1000 nodes in the Azure CNI Overlay.
Screenshot from the docs:
I deployed AKS with the CNI with Overlay option. The things that were deployed were:
- Two managed identities (these don't play a role I assume)
- A Load Balancer with 2 FrontendIP Configurations and two Backend Pools (aksOutboundBackendPool and another one called "kubernetes")
- I realized that when I deployed more nodes each backend pool list would grow with every node
- 2 FrontendIP Configurations are actually 1 configuration with Load Balancing rule (1st Public IP) and 1 configuration with Outbound rule (2nd Public IP)
- A Virtual Machine Scale Set which acts as a backend pool
- Network Security Group attached to the VMSS
I validated the limitations of Networking Related resources in Azure Networking Limitations and also I spotted that when adding a new node pool there is this piece of information:
Therefore, I don't know where does limit of 1000 nodes actually come from.
