/tags/sysadmin/ Recent content in Sysadmin on unixawy.com | Security Blog Hugo en-us Tue, 05 Sep 2017 04:20:05 +0000 /run-mysql-cluster-multi-masters-high-availability/ Tue, 05 Sep 2017 04:20:05 +0000 /run-mysql-cluster-multi-masters-high-availability/ A comprehensive production guide to architecting, deploying, scaling, and managing a distributed, multi-master MySQL NDB Cluster using Oracle MySQL Cluster Manager (MCM). /iptables-prerouting-postrouting/ Thu, 14 Jul 2016 16:08:25 +0000 /iptables-prerouting-postrouting/ A guide to implementing complex traffic redirection and routing across multi-homed Linux servers using Netfilter PREROUTING (DNAT) and POSTROUTING (SNAT/MASQUERADE). /docker-crash-course/ Mon, 30 May 2016 03:00:06 +0000 /docker-crash-course/ A comprehensive guide to Docker core concepts, daemon architecture, interactive vs. detached modes, port mapping, and image customization. /ssh-tunnelling/ Wed, 12 Aug 2015 23:18:08 +0000 /ssh-tunnelling/ A practical guide to SSH port forwarding: local port forwarding (-L), dynamic SOCKS proxies (-D), and reverse remote tunnels (-R) for bypassing NAT and firewalls. /password-policy-with-pam_cracklib/ Mon, 03 Aug 2015 18:33:37 +0000 /password-policy-with-pam_cracklib/ A practical guide to enforcing strict password complexity, dictionary checks, and immediate expiration across Linux accounts using pam_cracklib. /pluggable-authentication-modules/ Mon, 03 Aug 2015 16:51:56 +0000 /pluggable-authentication-modules/ A comprehensive guide to Linux Pluggable Authentication Modules (PAM): management groups, control flags, module stacks, and configuration architecture. /users-in-shadow-file-explanation/ Thu, 16 Jul 2015 01:09:24 +0000 /users-in-shadow-file-explanation/ A detailed breakdown of the 9 fields in the Linux /etc/shadow file, password hash algorithms ($1, $5, $6), epoch timestamp math, and account aging with chage. /aide-intrusion-detection-environment/ Tue, 14 Jul 2015 05:05:05 +0000 /aide-intrusion-detection-environment/ How to configure Advanced Intrusion Detection Environment (AIDE) on Linux to detect unauthorized file tampering, privilege escalations, ACL changes, and rootkits. /umask-permissions-explanation/ Fri, 10 Jul 2015 07:16:00 +0000 /umask-permissions-explanation/ How the Linux umask (user mask) controls default permissions on newly created files and directories, binary bitmask calculation, and security hardening. /removable-disk-could-lead-to-privilege-escalation/ Sun, 05 Jul 2015 22:41:43 +0000 /removable-disk-could-lead-to-privilege-escalation/ How auto-mounted removable USB drives and external filesystems without nosuid and noexec mount options allow local privilege escalation on Linux systems. /persistent-mount-for-luks-with-unlock-key/ Sun, 05 Jul 2015 04:18:13 +0000 /persistent-mount-for-luks-with-unlock-key/ How to configure automated headless unlocking and persistent mounting for LUKS block devices on system boot using keyfiles, /etc/crypttab, and /etc/fstab. /rpm-integrity-and-scripts/ Tue, 30 Jun 2015 02:54:40 +0000 /rpm-integrity-and-scripts/ How to inspect GPG signatures, checksum digests, and embedded root install scriptlets in RPM packages to prevent software supply-chain compromises in Red Hat and CentOS. /iptables-redirect-ports-one-port/ Thu, 08 Jan 2015 21:27:08 +0000 /iptables-redirect-ports-one-port/ How to use Linux Netfilter iptables PREROUTING rules with DNAT to redirect broad port ranges or all incoming TCP traffic to a single destination port.