#security
All articles tagged #security — practical guides from production experience.
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15 posts tagged #security · page 1 of 2
Log Analysis for Security Investigations: Windows Event Logs and Web Server Access Logs
A practical guide to log analysis for security investigations — Windows Event Viewer, critical Event IDs, Apache access log parsing, and the Linux command-line tools that make manual log analysis fast and effective.
SSH Connection Refused Linux: Fix Guide
Fix SSH connection refused on Linux — diagnose why SSH won't connect, check sshd service and firewall, recover from lockout, and harden SSH without breaking access.
Permission Denied Linux: Fix with chmod and chown
Fix 'permission denied' errors in Linux — read permission bits correctly, use chmod and chown safely, debug with ls -la and stat, and avoid common mistakes that break applications.
Nginx Rate Limiting Configuration: Practical Guide With Examples
Configure nginx rate limiting with limit_req_zone and limit_req — with real examples for API protection, login endpoints, and burst handling in production.
Linux Check Listening Ports with ss: Complete Guide
Check listening ports in Linux with ss — see TCP and UDP listeners, find which process owns each port, filter by interface binding, and detect unexpected services.
Linux Check Last Login Users: last, lastlog, who
Check last login history in Linux using last, lastlog, and who — find recent logins, failed attempts, and suspicious access patterns for security audits.
iptables Block IP: Practical Examples for Linux
Block IPs with iptables — block single IP, IP range, port-specific rules, make rules persistent, and use ipset for large block lists. Real production examples.
How to Check Listening Ports in Linux (2026 Guide)
Check listening ports in Linux with ss, netstat, lsof, and nmap — know which service owns each port, detect unexpected listeners, and troubleshoot connection refused errors.
How to Check Firewall Status in Linux: iptables, firewalld, ufw
Check firewall status in Linux using iptables, firewalld, and ufw — see active rules, verify port access, and diagnose whether firewall is blocking traffic.