910 B
Kubernetes Networking Options
kops sets up networking on AWS using VPC networking, where the master allocates a /24 CIDR to each Pod, drawing from the Pod network. Routes for each node are then configured in the AWS VPC routing tables.
One important limitation to note is that an AWS routing table cannot have more than 50 entries, which sets a limit of 50 nodes per cluster. AWS support will sometimes raise the limit to 100, but performance limitations mean they are unlikely to raise it further.
Because k8s modifies the AWS routing table, this means that realistically kubernetes needs to own the routing table, and thus it requires its own subnet. It is theoretically possible to share a routing table with other infrastructure (but not a second cluster!), but this is not really recommended.
kops will support other networking options as they add support for the daemonset method of deployment.