Guidelines for IPAM configuration¶
To avoid significant issue during the installation process, follow these guidelines to either use the appropriate size network in Azure or take the necessary actions to fit within the subnet.
Configure the subnet and the virtual network associated with the primary interface of the Azure VMs with an adequate address prefix/range. The number of required IP addresses depends on the workload and the number of nodes in the cluster.
For example, for a cluster of 256 nodes, make sure that the address space of the subnet and the virtual network can allocate at least 128 * 256 IP addresses, in order to run a maximum of 128 pods concurrently on a node. This is in addition to initial IP allocations to VM network interface card (NICs) during Azure resource creation.
Accounting for the allocation of IP addresses to NICs that occur during VM
bring-up, set the address space of the subnet and virtual network to
10.0.0.0/16. This ensures that the network can dynamically allocate
at least 32768 addresses, plus a buffer for initial allocations for
primary IP addresses.
The Azure IPAM module queries the metadata of an Azure VM to obtain a list
of the IP addresses that are assigned to the VM NICs. The IPAM module
allocates these IP addresses to Kubernetes pods. You configure the IP
ipConfigurations in the NICs associated with a VM or
scale set member, so that Azure IPAM can provide the addresses to Kubernetes