Core network policy versions in AWS Cloud WAN - AWS Network Manager
Core network policy sections

Core network policy versions in AWS Cloud WAN

Create a version of your current network policy any time you want to make changes to your network. Policy versions can be created using the console, through either the visual editor mode or directly in JSON, or you can download a version of any policy and make changes to that policy in any JSON editor. Once you create a new version of a policy you can compare that version against an older version to view changes.

New versions of policies are not automatically deployed, so once you create a policy version you can deploy that policy at a time of your own choosing. You can also restore any out-of-date policy to become the new current version.

The name of each policy version you create is numbered incrementally from the LATEST version. For example, if the LATEST policy version ID is 1, and you create a new version of that policy, the new version is numbered 2. The latest version is displayed on the Policy versions screen with a LATEST status, indicating that the new policy is ready to deploy.

Change set states can be any of the following:

  • Ready to execute — A policy version change set and a new policy version have been created. This policy version was verified with no issues and is in a state where it can be deployed as the new LIVE policy. You can have multiple policy versions in this state, but you can only have one LIVE policy. When deployed, the policy change set state changes to Execution succeeded. For the steps to deploy a policy change set state, see Deploy an AWS Cloud WAN core network policy version.

  • Execution succeeded — The policy version was deployed as the new LIVE policy.

  • Out of date — If you have multiple policy version change sets, any policy version that's older than the current LIVE policy is set to out-of-date, indicating that it's older than the LIVE policy. You can restore an out-of-date policy. For instructions, see Restore an out-of-date AWS Cloud WAN core network policy version.

  • Failed generation — An error prevented the policy from generating. Choose the Failed generation link to see details about the failure.

  • Pending generation — A policy version was created and is waiting to be generated. When the version has been generated, the change set state changes to Ready to execute. If policy generation failed, this state changes to Failed generation.

You can create a core network policy version through either the AWS Cloud WAN console or by creating or modifying a JSON file.

Topics

Core network policy sections

The following are the parts of a core network policy and describe how each of these work. If you're using either the console or a JSON file, a policy version is always composed of these sections.

Network configuration

Use Network configuration to configure the Border Gateway Protocol (BGP) Autonomous System Number (ASN) for your core network. The valid ranges are 64512 - 65534 and 4200000000 - 4294967294. You can also configure the Inside CIDR blocks that are used for BGP peering on Connect peers. For more information on Transit Gateway Connect attachment and Connect peers, see the Transit Gateway Connect documentation. Using the network configuration, you can also configure the edge locations where you want the Core Network Edges to be available. At any time, you can add or remove edge locations through the network configuration.

See the following for the steps to configure your network:

Segments

The Segments section of a policy allows to divide your global network into separate isolated networks. Here you create a segment, and then define the attachment communication mapping. Each segment creates a dedicated routing domain. You can create multiple network segments within your global network. Resources that are connected to the same segment can only communicate within the segment. Optionally, you can also set resources in the same segment to be isolated from each other, with access only to shared services. With segments, AWS maintains a consistent configuration across AWS Regions for you, meaning that you don't need to synchronize configuration across every device in your network.

See the following for the steps to add segments to your core network:

Network function groups

A network function group is composed of a group of attachments used to steer those attachments to network security group functions. For example, you might create a network function group that steers traffic from a production segment through an inspection VPC directly to the Internet.

Optionally use the Network function groups page to create a group that allows you to insert AWS and third-party networking and security services on Cloud WAN using your policy document. After creating a network function group you'll create a segment action that defines how you want to steer the segments and attachments for the network function group.

Segment actions

Segment actions allow you to optionally share your segments, create routes, or create a service insertion action for a network functions group.

  • Segment sharing — Segment sharing is bidirectional by default. When you create a segment share between two segments, routes from both segments are automatically advertised to each other. For example, you might share a segment named test with another segment named dev. Routes from test are advertised to dev, and vice versa. To make routes in shared segments unidirectional, create a deny list filter to share routes from one segment to the other, but not vice versa. Using the previous example, you could make a deny list filter that prevents routes from test being advertised to dev. For more information on creating the deny list for a segment, see Add a segment to an AWS Cloud WAN core network policy version.

  • Segment routes — Create a segment route to define a static route within a segment.

  • Service insertion — Create a service insertion action that allows you to insert a network function within a segment or across segments. This action can either be send via (east-west) or send to north-south). For more information about traffic actions and modes see Traffic actions and modes. You can additionally choose to specify which edge locations you want to use. Service insertion uses a default order for choosing the edgte locations. However, you can specify which edges you want to use as well as which edge is the preferred edge.

See the following for the steps to set segment actions:

Attachment policies

Attachment policies control how your attachments map to your segments or network function groups. You create a network function group attachment policy using either the AND or OR subset of conditions along with either the full tag name or tag value.

See the following for the steps to create a network functions group attachment policy: