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Creating Firewalls Using Roles

Even within a private network like DN, it's a good idea to restrict the types of communication which can occur between different kinds of devices. For example, web server machines might need to communicate with database machines over certain ports, but they should not be able to ssh into user laptops. These access rules are managed in DN through the use of roles. This guide will explain what roles are and how they are used to manage both identity and access within a DN network.

In DN, a role represents the primary purpose and group-identity of a host. For example, you might create roles such as Admin Endpoint, User Endpoint, WWW Server, etc. Each machine that you create should be assigned a role when it is created. Firewall rules are configured for inbound traffic at the role level. Newly created roles allow only ICMP traffic so that ping requests can be used for troubleshooting. All other inbound traffic is denied by default, and the rules can be configured to allow other kinds of traffic from machines belonging to specific roles.

Note that currently, due to the way identity is securely managed in DN, role names cannot be changed after they are created, and hosts cannot be edited to change their role. The firewall rules of roles can be changed at any time, and updates will be sent out to all affected machines automatically.

To create a role, visit the Roles page of your DN admin panel. A default “Lighthouse” role was created automatically when your account was provisioned. Let's create a new www-internal role to use for web servers of an internal website. Start by clicking the Add button on the top right of the page and filling out the role name (required) and a description (optional).

Add a new role form, requiring a name optional description

We'll create two more roles for endpoint-employee and endpoint-admin. We can see that they have been added to the list of roles, and that they all have one rule.

List of roles in DN showing four roles: Lighthouse, endpoint-admin, endpoint-employee, and `www-internal`

Let's click on www-internal to open that role's page.

Page showing details for role `www-internal`, showing the role ID, description, and a default inbound firewall rule allowing `ICMP` from all hosts, so you can ping the host

Now, we want to allow inbound TCP traffic on port 443 from both kinds of endpoints, so that HTTPS requests to the internal page from administrators and employees are allowed. First, click the “Add firewall rule” button, then choose TCP for the protocol, type 443 as the port range, and select the endpoint-employee role from the Allowed role dropdown. We've entered a description as well, which is a good idea to help provide context for rules.

Add inbound firewall rule form requesting a protocol choice, a port/port range, an allowed role, and an optional description

We'll add the same rule for endpoint-admin so they can access the website, as well as one final rule to allow TCP:22 for admins, so that they can also ssh into web server boxes. The final result looks like this:

A Role details page with a couple of different firewall rules, and an enabled "Save role" button that shows that you still need to save

Changes to roles are not saved until the “Save role” button is clicked, to minimize the number of updates sent to hosts on the network.

After saving, let's add a web server host. Visit the Hosts page, and click the “Add” button. Choose a name, and click on the Role dropdown. Hosts (as well as lighthouses and relays) are only allowed to have one role.

Add a host form with an open "select a role" dropdown hovering over `www-internal`

Note, that it's also possible to create new roles along with the host, by choosing the “Add new role” option. Roles added this way will only allow ICMP traffic, but the firewall rules can be edited as shown above.

Add a host form showing "Add new role" selected in the dropdown with a new field named "Role name" to allow creating a new role alongside the new host

Roles can be deleted so long as there are no hosts, lighthouses, or relays using the role. To delete a role, choose the “Delete role” option from the role's three-dot menu on the Roles page, and then confirm your decision in the confirmation dialog.

The more menu for `endpoint-admin` on the Roles page has been opened, and the "Delete role" option is hovered