CentOS/RHEL

There may be a case when you need to add or remove ports when firewalld is disabled. In such cases “firewall-offline-cmd” can be used as it is an offline command-line client of the firewalld daemon. A port can be added or removed via firewall-offline-cmd in case firewalld is not active. Note: Please make sure to […]

firewall-offline-cmd is an offline command-line client of the firewalld daemon. It should be used only if the firewalld service is not running. A port can be added or removed via firewall-offline-cmd in case firewalld is not active. firewall-offline-cmd Command Examples 1. For adding a port: # firewall-offline-cmd –port=XXXX:tcp 2. For removing a port: # firewall-offline-cmd […]

lvsd is a daemon to control the Red Hat clustering services. lvsd reads in the cluster configuration file lvs.cf, calls ipvsadm to maintain the IPVS routing table, and nanny to perform monitoring services. lvsd Command Options

SELinux can either be in an enabled or a disabled state. In order to check in which state it is running, we can make use of the getenforce command. There are two modes in which SELinux runs: There are two modes in which SELinux runs: Enforcing: This is the enabled state where all rules are […]

We can change the SELinux modes from enforcing to permissive and vice versa during runtime by using the setenforce command. Before and after changing the SELinux mode, we must ensure the current mode by using the getenforce command. SELinux can either be in an enabled or a disabled state. In order to check in which […]

IP sets are stored collections of IP addresses, network ranges, MAC addresses, port numbers, and network interface names. The iptables tool can leverage IP sets for more efficient rule matching. For example, let’s say you want to drop traffic that originates from one of several IP address ranges that you know to be malicious. Instead […]