Firewall

cPguard firewall is built on nftables, offering greater flexibility and performance compared to legacy iptables. Since it works at the system level, it operates independently of any control panel (including RunCloud). This ensures your server remains protected at all times. You can manage rules and settings directly through our firewall module.

The cPguard firewall includes powerful features such as IP and country-based whitelisting/blacklisting, extended rule imports, temporary bans with expiry, port filtering, DoS/SYN-flood protection, real-time IPDB integration, AI bot protection, and Fail2Ban support for service-level brute-force defense. These features ensure proactive security and complete control over inbound and outbound traffic. For each function, you can manage rules easily through the UI interface, or use CLI options, both of which are available for flexibility.

The Firewall settings and IP blacklist/whitelist and temporary bans can be managed directly from UI.

All tasks can also be performed via the CLI, and you can view the available options using the following commands:

The firewall can be easily enabled or disabled using the toggle option, and restarts can also be initiated directly from the UI.

You can check status, enable, disable or restart the firewall module using the following command :

1. IP block management

a. Check IP

To check if IP is in any firewall list, input the IP in the given box.

b. Whitelist/Blacklist IP or CIDR:

You can manage whitelist and blacklist IPs or CIDRs through the UI by entering the IP in the provided box, adding a reason in the comment section, and removing entries when needed.

To view all whitelisted and blacklisted IPs, there are options like “View Whitelist” and “View Blacklist.” By clicking these, you can see all the IPs added along with their reasons, and you also have the option to add new entries directly from this view.

c. Temporary ban

IPs may be temporarily blocked by DoS protection, Fail2Ban, SYN-Flood, etc. If you notice an IP is blocked, you can unblock it by entering the IP in the provided box and clicking Unblock. Default expiry is 24 hours.

If you want to temporarily block an IP, this can also be done from the Block IP section. Enter the IP, set the expiry time, and click Block. You can choose to block the IP for minutes, hours, or days as needed.

2. IPDB distributed firewall

The IPDB firewall can be managed from this section. You can turn it on or off using the toggle, and you can also enable or disable IPDB logging through the same toggle.

3. DoS Protection

To configure DoS protection, enable it using the toggle and enter the maximum requests allowed per minute in the provided box.

4. Configure AI bots and Fail2ban

AI bot protection settings and Fail2Ban settings, which can be enabled by switching the toggle to On.

5. Country filtering

You can whitelist or blacklist entire countries using their ISO codes (e.g., US, CN), with options to add, remove, or view the list of allowed or blocked countries.

6. SYNFLOOD

A SYN flood is a type of Denial-of-Service (DoS) attack where an attacker sends a large number of TCP connection requests (SYN packets) but never completes the handshake, exhausting server resources and making it unavailable to legitimate users.

Note: It is not recommended to enable SYN protection unless you notice a SYN flood attack.

The SYN flood rate configuration sets a limit on how many SYN requests are allowed within a specific time interval (e.g., 10/minute). This helps the firewall differentiate between normal traffic spikes and malicious floods, blocking excessive SYN packets before they overwhelm the server.

Enable SYN Flood Protection configures the firewall to defend against TCP SYN packet DoS attempts. It is important to set the rate carefully to minimize false positives, otherwise visitors may experience connection issues. You can monitor for blocked attempts in /var/log/messages under SYNFLOOD Blocked.

The SYN flood burst value defines how many SYN packets are allowed to pass through in a short burst before the rate limiting kicks in.

• Burst allows a temporary spike in connections (e.g., when many users connect at once).

• After the burst limit is reached, the firewall enforces the rate limit (e.g., 10/minute).

Example: If you set --synflood-burst 20 and --synflood-rate 10/minute, the firewall will allow up to 20 SYN packets immediately, but then only permit 10 new SYN packets per minute after that.

7. Port filter configuration

Port Filtering allows you to control inbound and outbound traffic by defining which TCP and UDP ports are permitted. When enabled, all ports are blocked by default except those explicitly allowed. You can manage input and output ports separately for both TCP and UDP, with options to add, remove, or list the allowed ports. This ensures only required services are accessible while closing all unnecessary ports for better security.

You can enter a range of ports in the input box. To define a range, use a dash (-) between the starting and ending port numbers. For example, 30000-35000 will cover every port from 30000 up to 35000. You can also mix single ports and ranges, like 22,80,443,30000-35000, to allow or block multiple specific ports together.

8. Whitelist/Blacklist Source File

You can manage extended whitelist and blacklist sources by importing IPs directly from files. This allows you to add, remove, or list source files containing multiple IP addresses, making it easier to handle large or frequently updated blocklists and whitelists in a centralized way. The available CLI options are: