To block the entire subnet, run: $ sudo firewall-cmd -permanent -add-rich-rule="rule family='ipv4' source address='192.168.2.0/24' reject" To block an IP address, ‘ rich rules’ are used for this purpose.įor example to block the IP 192.168.2.50 run the command: $ sudo firewall-cmd -permanent -add-rich-rule="rule family='ipv4' source address='192.168.2.50' reject" So far, we have seen how you can add and remove ports and services as well as whitelisting and removing whitelisted IPs. If you wish to remove a whitelisted IP on the firewall, use the -remove-source flag as shown: $ sudo firewall-cmd -permanent -remove-source=192.168.2.50įor the entire subnet, run: $ sudo firewall-cmd -permanent -remove-source=192.168.2.50/24 For example to allow an entire subnet in the 255.255.255.0 subnet, execute.
You can also allow a range of IPs or an entire subnet using a CIDR (Classless Inter-Domain Routing) notation. To allow a single IP address across the firewall, execute the command: $ sudo firewall-cmd -permanent -add-source=192.168.2.50 To block a service, for instance, FTP, execute: $ sudo firewall-cmd -remove-service=https To allow a service such as https, execute the command: $ sudo firewall-cmd -add-service=https Network services are defined in the /etc/services file. Similarly, blocking a UDP port will follow the same syntax: $ sudo firewall-cmd -remove-port=53/udp -permanent $ sudo firewall-cmd -remove-port=22/tcp -permanent To block a TCP port, like port 22, run the command. The -permanent flag ensures that the rules persist even after a reboot. Similarly, to add a UDP port, specify the UDP option as shown: $ sudo firewall-cmd -add-port=53/udp -permanent Note that you have to specify whether the port is a TCP or UDP port after the port number: $ sudo firewall-cmd -add-port=22/tcp -permanent To add a port, say port 443 for HTTPS, use the syntax below. Once done with the configurations, always ensure that you reload the firewall for the new rules to take effect.
Firewalld allows you to add and block ports, blacklist, as well as whitelist IP, addresses to provide access to the server. Now that we have firewalld running, we can go straight to making some configurations. Check Firewalld Status Configuring Rules using Firewalld The output below confirms that the firewalld service is up and running.
0 kommentar(er)
