# Network Topologies in Kops

Kops supports a number of pre defined network topologies. They are separated into commonly used scenarios, or topologies.

Each of the supported topologies are listed below, with an example on how to deploy them.

## AWS

Kops supports the following topologies on AWS

|      Topology     |   Value    | Description                                                                                                 |
| ----------------- |----------- | ----------------------------------------------------------------------------------------------------------- |
|   Public Cluster  |   public   | All masters/nodes will be launched in a **public subnet** in the VPC                                        |
|   Private Cluster |   private  | All masters/nodes will be launched in a **private subnet** in the VPC                                       |
|     Private Masters Public Nodes    |   privatemasters  | All masters will be launched into a **private subnet**, All nodes will be launched into a **public subnet** |

[More information](http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Subnets.html) on Public and Private subnets in AWS

Taken from the AWS documentation :

##### Public Subnet
If a subnet's traffic is routed to an Internet gateway, the subnet is known as a public subnet.

##### Private Subnet
If a subnet doesn't have a route to the Internet gateway, the subnet is known as a private subnet.-



#### Defining a topology on create

To specify a topology use the `--topology` or `-t` flag as in :

```
kops create cluster ... --topology public|private|privatemasters
```


#### Defining a topology in the cluster configuration

The topology definition in the kops configuration is as follows

```
topology:
    type: public|private|privatemasters
```

Where kops will default to a public topology

```
topology:
    type: public
```