Freaks City

System Initialization & Security Module Alignment Before applying network policies, ensure underlying security modules align with you're operational requiremants. Disabling SELinux enforcement and halting the firewall daemon can be executed via the following sequence: # Immediately disable SELinux enforcing state setenforce 0 >/dev/null ...

Firewall Management Check firewall status: systemctl status firewalld Start firewall: systemctl start firewalld List all firewall rules and open ports: firewall-cmd --list-all Open a specific port (e.g., 8080/tcp): firewall-cmd --add-port=8080/tcp --permanent Reload firewall to apply changes: firewall-cmd --reload Verify if a port is open: ...

After installing Apache Tomcat on a CentOS server, you can successfully access it via http://localhost:8080 from the local machine. However, attempts to reach the server from other devices on the same network fail, eventhough ICMP ping requests are answered. The root cause is typically the system firewall blocking incoming connections on port 8 ...

Setting Up YUM Repository sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak sudo curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo sudo yum makecache Initial Configuration ...

Accelerate SSH Connections To reduce SSH connection latency, adjust the server-side configuration in /etc/ssh/sshd_config. First, back up the original file: cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak Edit the configuration file and apply these changes: Set GSSAPIAuthentication to no (typically around line 79). Uncomment and set UseDNS t ...