kubernetes-the-hard-way/docs/11-pod-network-routes.md

Provisioning Pod Network Routes

Pods scheduled to a node receive an IP address from the node's Pod CIDR range. At this point pods can not communicate with other pods running on different nodes due to missing network routes.

In this lab you will create a route for each worker node that maps the node's Pod CIDR range to the node's internal IP address.

There are other ways to implement the Kubernetes networking model.

The Routing Table

In this section you will gather the information required to create routes in the kubernetes-the-hard-way VPC network.

Create the Azure route table

az network route-table create --group kubernetes-the-hard-way --name kubernetes-the-hard-way-rt

Routes

Create network routes for each worker instance:

for i in 0 1 2; do
  az network route-table route create \
    --resource-group kubernetes-the-hard-way \
    --name kubernetes-the-hard-way-route-10-200-${i}-0-24 \
    --route-table-name kubernetes-the-hard-way-rt \
    --next-hop-type VnetLocal
    --next-hop-ip-address 10.240.0.2${i}
done

List the routes in the kubernetes-the-hard-way VPC network:

az network route-table route list --resource-group kubernetes-the-hard-way --route-table-name kubernetes-the-hard-way-rt

output

NAME                            NETWORK                  DEST_RANGE     NEXT_HOP                  PRIORITY
default-route-081879136902de56  kubernetes-the-hard-way  10.240.0.0/24  kubernetes-the-hard-way   1000
default-route-55199a5aa126d7aa  kubernetes-the-hard-way  0.0.0.0/0      default-internet-gateway  1000
kubernetes-route-10-200-0-0-24  kubernetes-the-hard-way  10.200.0.0/24  10.240.0.20               1000
kubernetes-route-10-200-1-0-24  kubernetes-the-hard-way  10.200.1.0/24  10.240.0.21               1000
kubernetes-route-10-200-2-0-24  kubernetes-the-hard-way  10.200.2.0/24  10.240.0.22               1000

Next: Deploying the DNS Cluster Add-on