# Getting started with a Classic AWS Network Firewall policy
This tutorial walks you through creating a Classic AWS Network Firewall firewall using the AWS Management Console. A Classic policy uses stateless rule groups and stateful rule groups. You create a stateless rule group and a stateful rule group, combine them in a Classic firewall policy, create a firewall, and route your VPC traffic through the firewall endpoint. For a tutorial that uses a Next Generation policy instead, see [Getting started with a Next Generation policy](getting-started-v2.md). For the differences between the two policy types, see [AWS Network Firewall firewall policy versions](firewall-policy-versions.md).
This tutorial uses the same VPC prerequisites as described in [Before you begin](getting-started.md#getting-started-prerequisites).
**Topics**
+ [Step 1: Create rule groups](#getting-started-add-rule-groups)
+ [Step 2: Create a firewall policy](#getting-started-configure-firewall-policy)
+ [Step 3: Create a firewall](#getting-started-create-firewall)
+ [Step 4: Update your Amazon VPC route tables](#getting-started-update-route-tables)
+ [Step 5: Remove the firewall and clean up your resources](#getting-started-clean-up)
## Step 1: Create rule groups
Rule groups are reusable collections of network filtering rules that you use to configure firewall behavior. In this step, you create a stateless rule group and a stateful rule group. For information about rule groups, see [Managing your rule groups](rule-groups.md).
**To name a stateless rule group and choose its type**
1. Sign in to the AWS Management Console and open the Amazon VPC console at [https://console.aws.amazon.com/vpc/](https://console.aws.amazon.com/vpc/).
In the navigation pane, under **Network Firewall**, choose **Network Firewall rule groups**, and then choose **Create**.
1. On the **Describe rule group** page, enter a **Name** for the rule group, and optionally a description. You use the name to identify the rule group when you add it to your firewall policy later in the tutorial. You can't change the name after you create the rule group. Choose **Next**.
1. On the **Choose rule group type** page, for **Rule group version**, select **Classic**. For the rule group type, select **Stateless rule group**. Choose **Next**.
After you select the rule group type, configure the rule and set the capacity to finish creating the stateless rule group.
**To configure rules and create the stateless rule group**
1. On the **Configure rules** page, enter the rule specifications to create a stateless rule that blocks all packets coming from the source IP address CIDR range `10.0.0.0/24`: set the priority to **10**, leave the protocol at **All**, for the source select **Custom** and enter **10.0.0.0/24**, leave the source port at **Any**, for the destination leave **Any IPv4 address** selected, and for **Rule action** select **Drop**. Choose **Add rule** to add your rule to the **Rules** list.
1. On the same page, under **Capacity sizing**, leave **Allow room to grow** selected (the recommended option), or select **Match current rules** or **Custom capacity** (a value from 1 to 30,000). You can't change the capacity after you create the rule group. Choose **Next**.
1. On the **Review and create** page, review the settings for the rule group, then choose **Create**.
Your new rule group is added to the list in the **Rule groups** page.
**To create a stateful rule group**
1. From the **Rule groups** page, choose **Create**.
1. On the **Describe rule group** page, enter a **Name** for the stateful rule group, and optionally a description. Choose **Next**.
1. On the **Choose rule group type** page, for **Rule group version**, select **Classic**. For the rule group type, select **Stateful rule group**. For **Rule group format**, select **Text rule builder**. For **Rule evaluation order**, leave **Strict order** selected (the recommended option). Choose **Next**.
1. On the **Rule group variables** page, choose **Next** to accept the defaults.
1. On the **Configure rules** page, under the Suricata compatible rule string, copy and paste the following rule. This rule drops TLS traffic for a specific target domain:
```
drop tls $HOME_NET any -> $EXTERNAL_NET any (ssl_state:client_hello; tls.sni; content:"evil.com"; startswith; nocase; endswith; msg:"matching TLS denylisted FQDNs"; priority:1; flow:to_server, established; sid:1; rev:1;)
```
1. On the same page, under **Capacity sizing**, leave **Allow room to grow** selected (the recommended option). You can't change the capacity after you create the rule group. Choose **Next**.
1. On the **Review and create** page, review the rule group, then choose **Create**.
Your stateless rule group and your stateful rule group are listed in the **Rule groups** page. You can now use these rule groups in your firewall policies.
## Step 2: Create a firewall policy
Firewall policies use rule groups and other settings to define the traffic filtering behavior for a firewall. In this procedure, you create a Classic policy using the rule groups that you created in the previous step. For information about firewall policies, see [Firewall policies in AWS Network Firewall](firewall-policies.md).
**To configure a firewall policy**
1. Sign in to the AWS Management Console and open the Amazon VPC console at [https://console.aws.amazon.com/vpc/](https://console.aws.amazon.com/vpc/).
In the navigation pane, under **Network Firewall**, choose **Firewall policies**, and then choose **Create firewall policy**. On the **Firewall policy details** page, for **Policy version** select **Classic** (for information about the policy types, see [AWS Network Firewall firewall policy versions](firewall-policy-versions.md)), and enter the name that you want to use for the firewall policy. You use the name to identify the policy when you associate it with your firewall later in the tutorial, and you can't change it after you create the policy. Then choose **Next**.
1. On the **Traffic inspection** page, leave the settings unset for this tutorial, and then choose **Next**.
1. On the **Add rule groups** page, in the **Stateful rule evaluation order and default actions** section leave the default rule evaluation order for this tutorial; in the **Stateful rule group** section choose **Add stateful rule groups**, select your stateful rule group, and choose **Add rule groups**; in the **Stateless default actions** section, under **Fragmented packets** select **Use the same actions for all packets** and for **Rule action** select **Forward to stateful rule groups** so that traffic your stateless rule group doesn't block is inspected by the stateful engine (Network Firewall only manages UDP packet fragments and silently drops packet fragments for other protocols); and in the **Stateless rule group** section choose **Add stateless rule groups**, select your stateless rule group, and choose **Add rule groups**. Then choose **Next**.
1. On the **Network and encryption** page, choose **Next** to accept the defaults for this tutorial.
1. On the **Review and create** page, review your settings (choose **Edit** for any area to return to the corresponding page in the wizard), and then choose **Create firewall policy**.
Your new firewall policy is added to the list in the **Firewall policies** page. You can now use your firewall policy in your firewalls.
## Step 3: Create a firewall
Firewalls associate the traffic filtering behavior of a firewall policy with the primary VPC where you want to filter traffic. In this procedure, you create a firewall using the firewall policy that you created in the previous step. For information about firewalls, see [Firewalls and firewall endpoints in AWS Network Firewall](firewalls.md).
**To start creating a firewall and set its attachment type**
1. Sign in to the AWS Management Console and open the Amazon VPC console at [https://console.aws.amazon.com/vpc/](https://console.aws.amazon.com/vpc/).
In the navigation pane, under **Network Firewall**, choose **Firewalls**, and then choose **Create firewall**.
1. On the **Describe firewall** page, for **Name**, enter the name that you want to use to identify this firewall. You can't change the name of a firewall after you create it. Choose **Next**.
1. On the **Attachment type** page, under **Attachment Details**, select **VPC**, select your VPC, and then select the **Availability Zone**, **Subnet**, and **IP address type** for the firewall subnet that you identified in [Before you begin](getting-started.md#getting-started-prerequisites). Choose **Next**.
After you set the attachment type, configure the remaining settings, associate your firewall policy, and create the firewall.
**To configure settings and create the firewall**
1. On the **Configure advanced settings** page, the settings are optional. For this tutorial, choose **Next** to accept the defaults.
1. On the **Associate firewall policy** page, select **Associate an existing firewall policy**, then select the firewall policy that you created in the prior procedure. Choose **Next**.
1. (Optional) On the **Add tags** page, add any tags that you want, then choose **Next**.
1. On the **Review and create** page, review the firewall configuration, and then choose **Create firewall**.
Your new firewall is listed in the **Firewalls** page. You've configured the firewall's behavior with the firewall policy and rule groups, and your firewall has an endpoint that's running in your VPC, ready to filter network traffic.
**Note**
Network Firewall supports up to 100 Gbps of network traffic per firewall endpoint. If you require more traffic bandwidth, you can split your resources into subnets and create a Network Firewall in each subnet.
The next step is to route the VPC's network traffic through the firewall endpoint. You insert it into the traffic flow between the internet gateway and your customer subnet.
## Step 4: Update your Amazon VPC route tables
After you create your firewall, you insert its firewall endpoint into your Amazon Virtual Private Cloud network traffic flow, in between your internet gateway and your customer subnet. You create routing for the firewall endpoint so that it forwards traffic between the internet gateway and your subnet. Then, you update the route tables for your internet gateway and your subnet, to send traffic to the firewall endpoint instead of to each other.
This procedure covers the high-level steps for route table management. For information about managing route tables for your VPC, see [Route tables](https://docs.aws.amazon.com/vpc/latest/userguide/VPC_Route_Tables.html) in the *Amazon Virtual Private Cloud User Guide*.
**To modify your route tables to insert a firewall endpoint between your internet gateway and your subnet**
1. Review your routing for the internet gateway and for your customer subnet, to determine the components used to route traffic between the two.
Record the current settings. You use them to reverse your changes at the end of the tutorial.
+ The internet gateway's route table typically has an entry with a destination set to your customer subnet's CIDR block and a target of `local`.
+ The subnet's route table typically has an entry with a destination set to `0.0.0.0/0` and a target set to the internet gateway ID.
1. Create a route table configuration for the firewall endpoint with the following two routes:
+ An entry that matches the internet gateway's route specification for traffic going to the customer subnet's CIDR block.
+ An entry that matches the subnet's route specification for traffic going to the internet gateway.
The firewall endpoint is now ready to filter and forward traffic between the internet gateway and the customer subnet. The endpoint only forwards traffic to its intended destination if it passes the inspection criteria that you defined in the rule groups and firewall policy.
1. Update the internet gateway's routing to modify the entry with a destination set to your customer subnet's CIDR block. Change the target to the firewall endpoint ID.
1. Update the customer subnet routing to modify the entry with a destination set to the internet gateway ID. Change the target to the firewall endpoint ID.
The firewall endpoint is now filtering all traffic between your internet gateway and customer subnet.
## Step 5: Remove the firewall and clean up your resources
You've now successfully completed the tutorial. To remove the firewall endpoint from your VPC and prevent your account from accruing AWS Network Firewall charges for the tutorial resources, revert your route table changes and clean up the Network Firewall resources that you created.
**To modify your route tables to remove the firewall**
1. Return the internet gateway and subnet route tables to the configurations they had at the start of the prior procedure. This stops traffic from routing to the firewall endpoint.
1. Remove the route table configuration for the firewall endpoint.
**To delete the firewall**
1. Sign in to the AWS Management Console and open the Amazon VPC console at [https://console.aws.amazon.com/vpc/](https://console.aws.amazon.com/vpc/).
1. In the navigation pane, under **Network Firewall**, choose **Firewalls**.
1. In the **Firewalls** page, select the firewall that you created for the tutorial.
1. Choose **Actions**, then choose **Delete**, and then confirm your request.
To avoid incurring further AWS Network Firewall charges, after you delete the firewall, also delete the firewall policy and the rule groups that you created for the tutorial.
**To delete the firewall policy and rule groups**
1. In the navigation pane, under **Network Firewall**, choose **Firewall policies**.
1. In the **Firewall policies** page, select the firewall policy that you created for the tutorial.
1. Choose **Delete**, and confirm your request.
1. In the navigation pane, under **Network Firewall**, choose **Network Firewall rule groups**.
1. In the **Rule group** page, select the name of the rule groups that you created for the tutorial, and then choose **Delete**.
You've successfully removed the firewall from your VPC traffic flow and removed all of the Network Firewall resources that you created for this tutorial.