Clavister
Overview
This guide explains how to integrate our cloud DNS filter with Clavister cOS Core firewalls. Connect to the WebUI by entering the management IP address of your Clavister device in your browser. Log in using your administrator credentials.
On Clavister cOS Core, changes made in the WebUI or CLI are staged in a pending state and do not take effect immediately. Remember to execute Save and Activate at the end of the procedure to apply your configuration.
Create DNS Objects in the Address Book
Before configuring the DNS servers on Clavister cOS Core, you must register the IP addresses as objects inside the Address Book.
Clavister cOS Core relies on an object-based configuration. Defining individual IPs and grouping them in the Address Book first makes it much faster to reference them across DNS settings, DHCP options, and firewall policies.
Once logged into the dashboard, navigate to Objects in the top menuand click on Address Book in the left sidebar. Click on Add and select IP4 Address to create the primary server:
- Name: DNS1
- Address: 185.236.104.104
Click OK, then click on Add and select IP4 Address again to create the secondary server:
- Name: DNS2
- Address: 185.236.105.105
Click OK. Next, group both addresses together so they can be easily referenced in your configurations. Click on Add and select IP4 Group:
- Name: DNS_Group
- Members: Select DNS1 and DNS2
Finally, click OK.
Configure DNS Addresses on Clavister
Once the Address Book objects are created, navigate to System in the top menuand click on DNS in the left sidebar.
Locate the DNS Servers section and assign the previously created objects:
- Primary DNS: DNS1
- Secondary DNS: DNS2
Finally, click OK.
Configure Dynamic DNS
If your internet connection uses a dynamic public IP address, you must configure the Dynamic DNS service to keep your network synchronized with our cloud platform.
You can skip this section if your ISP provides a static public IP address and you have already registered it in your cloud management dashboard.
Navigate to Network in the top menu, expand Network Services in the left sidebar, and click on Dynamic DNS. Click on Add and select dyn.com Dynamic DNS from the dropdown menu, then perform these steps:
- DNSName: Enter your registered domain or hostname.
- Username: Enter your account username.
- Password: Enter your account password.
- Confirm Password: Re-enter your account password to confirm.
Finally, click OK at the bottom of the form.
If you need to organize multiple entries, you can right-click on an existing item in the table and select Create Group to manage them in visual folders.
In case you prefer to configure the Dynamic DNS client via the command-line interface, access your virtual machine console and enter the following commands:
add DynDnsClientDyndnsOrg DNSName="yourdomain" Username="yourusername" Password="yourpassword"
activate
commitDistribute DNS on the Network
To distribute the DNS across the network, we must instruct the Clavister firewall to automatically deliver the DNS IPs to all computers, smartphones, and devices on the local network. This is done through the DHCP server settings.
Before proceeding, ensure you have already configured your cloud DNS servers globally under System > DNS (as explained in the previous steps).
Navigate to Network in the top menu, expand Network Services in the left sidebar, and click on DHCP Servers. Click on Add and select DHCPv4Rule, then fill in the configuration options:
- Name: Enter an identifier for the rule, such as LAN_DHCP.
- Interface Filter: Select the internal LAN interface, for example, If1.
- IP Address Pool: Select your local address pool or subnet range object.
- Netmask: Select 255.255.255.0.
- Default GW: Select your internal LAN interface gateway IP, such as If1_dns1.
- Domain: Enter your local domain name if applicable.
- Lease Time: Keep or adjust the default lease duration in seconds (e.g., 86400).
For the DNS distribution, leave the default selection enabled:
- Use the first two DNS Servers configured for this device: Keep this radio button checked so the firewall automatically distributes the primary and secondary FlashStart DNS servers configured in the global system settings. (Alternatively, select Specify DNS Servers if you need to override them with a custom pair).
Finally, click OK at the bottom of the form
Connected devices on the LAN will receive the new DNS settings once their current DHCP lease renews. To apply the changes immediately on a test machine, disconnect and reconnect to the network or run ipconfig /renew in the command prompt.
Optional: Prevent Bypass and Block Unauthorized DNS Traffic
To prevent users from bypassing your security settings using custom or public DNS servers (such as 8.8.8.8 or 1.1.1.1), you can enforce strict firewall policies. Read our dedicated guide Prevent Unauthorized DNS Traffic on Clavister to secure your network perimeter.
Save and Activate the Configuration
To make all changes active on Clavister cOS Core, click on Configuration in the top-right barand select Save and Activate, then click OK to confirm.
When activating changes via the CLI (activate), you must type commit within 30 seconds to permanently confirm the configuration, otherwise the firewall will automatically roll back to the previous state as a safety measure.