Who has an IP-address in Kubernetes?
- each Node has its own address
- each pod has its own internal address
How does a Pod receive his ip address?
- When Kubernetes is initially configured it creates an internal private network (i.e 10.244.0.0)
- all the pods are attached to it
- when multiple pods are created, each one gets his own ip from this network assigned (first: 10.244.0.2, second: 10.244.0.3)
- pods can communicate with each other through this ip, but not a good idea, since it can change
What is the initial challange with Networking in Kubernetes?
Example scenario: two nodes (192.168.1.2 and .3) with each one pod (10.244.0.2)
When a Kubernetes Cluster is set up, it does not handle automatically the issue, that both pods have the same internal IP
- Kubernetes expects us to set up a networking solution that meets two criterias
What criterias are expected from Kubernetes to be solved via a networking solution?
- all containers/pods can communicate with one another without Network address translation (NAT)
- all nodes can communicate with all containers and vice-versa without NAT
Name a few possible networking solutions?
- Cisco
- cilium
- flannel
- NSX T
Depending on the Platform, the Kubernetes cluster is deployed on
How does the networking work with multiple nodes in the cluster?
We use a custom networking to manage the network and assign different network addresses for each node in the network
- Creates a virtual network, where all nodes and pods are assigned their unique IP address
