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](https://cloud.google.com/compute/docs/vpc/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](https://kubernetes.io/docs/concepts/cluster-administration/networking/#how-to-achieve-this) to implement the Kubernetes networking model.

## The Routing Table

**On each worker node**, add the following routes:

```bash
ip route add 10.200.0.0/24 via 192.168.8.20
ip route add 10.200.1.0/24 via 192.168.8.21
ip route add 10.200.2.0/24 via 192.168.8.22
```

> Don't take care of the `RTNETLINK answers: File exists` message, it appears just when you try to add an existing route, not a real problem.

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

```bash
ip route
```

> Output:

```bash
default via 192.168.8.1 dev ens18 proto static
10.200.0.0/24 dev cnio0 proto kernel scope link src 10.200.0.1 linkdown
10.200.0.0/24 via 192.168.8.20 dev ens18
10.200.1.0/24 via 192.168.8.21 dev ens18
10.200.2.0/24 via 192.168.8.22 dev ens18
192.168.8.0/24 dev ens18 proto kernel scope link src 192.168.8.21
```

Next: [Deploying the DNS Cluster Add-on](12-dns-addon.md)