How to Pass an SSH Password in a Script with sshpass and Expect
Automate password-based SSH and SCP in Linux using sshpass, Expect, and SSH_ASKPASS, with safer password input, host-key handling, and key-based alternatives.
Mount Remote Directory with SSHFS on Linux & Windows
Mount a remote Linux directory over SSH with SSHFS on RHEL, Ubuntu, and Windows. Covers install, user mounts, permissions, fstab, jump hosts, SSHFS-Win UNC paths, and troubleshooting.
Configure OpenSSH Host-Based Authentication on Linux
Configure OpenSSH host-based authentication on Linux with HostbasedAuthentication, ssh-keysign, shosts.equiv, and verified host keys—plus hostname/DNS checks and safer alternatives.
How to Test SSH Connection in Linux (Port, Service & Login)
Test SSH connectivity in Linux step by step: check port 22, verify that sshd responds, test authentication, inspect server-side sshd status, and troubleshoot common SSH errors.
SSH Through a Jump Host with ProxyJump, ProxyCommand & SCP
Connect to private Linux servers through an SSH jump or bastion host using ProxyJump, ssh -J, ProxyCommand, and scp -J, with multi-hop routes and troubleshooting examples.
SSH into a VirtualBox VM from Host: NAT, Host-Only, and Bridged
SSH from your host into a Linux VirtualBox VM using NAT port forwarding (recommended), host-only networking, or a bridged adapter — with a mode decision table, guest SSH checks, and troubleshooting for 10.0.2.15 and VPN …
OpenSSH Host Certificates: Trust Servers with a Host CA
Use OpenSSH host certificates so clients trust one host CA through @cert-authority in known_hosts instead of enrolling every server host key — create a host CA, sign with ssh-keygen -h, configure HostCertificate on sshd, …
Fix "sshd: ssh-rsa algorithm is disabled" on RHEL
Understand sshd ssh-rsa algorithm is disabled on RHEL 9 and 10, when RSA-SHA2 logins still work, and when to upgrade clients or allow a scoped ssh-rsa exception.
Sign and Verify Files with SSH Keys Using ssh-keygen -Y
Sign files with ssh-keygen -Y sign, verify them with an allowed_signers file, signer identity, namespace, and stdin — no sshd or GPG required on OpenSSH 8.2 and later.
Fix SSH no matching key exchange method found
Fix SSH no matching key exchange method found by reading Their offer:, enabling the required KEX algorithm safely, and resolving follow-on host-key or cipher errors.
Fix SSH "Bad server host key: Invalid key length" Error
Fix SSH "Bad server host key: Invalid key length" caused by 1024-bit RSA host keys, RequiredRSASize, RHEL crypto policies, or stale known_hosts entries.
CKS Tutorial: Certified Kubernetes Security Specialist Course
Free CKS exam prep course covering all six Linux Foundation security domains, with hands-on kubeadm labs for kube-bench, Trivy, Cosign, Falco, and gVisor.
CKA Tutorial: Certified Kubernetes Administrator Course
Free CKA exam prep course covering all five Linux Foundation domains, with hands-on kubeadm labs on Rocky Linux VMs tested on Kubernetes 1.36.
CKAD Tutorial: Certified Kubernetes Application Developer Course
Free CKAD exam prep course covering all five Linux Foundation domains, with hands-on labs, 25 practice tasks, and a cheat sheet tested on Kubernetes 1.36.
Kubernetes Operator Tutorial - Build Production-Ready Operators
Free Kubernetes Operator course on CRDs, controller-runtime, and Go, Helm, and hybrid operators, with hands-on labs tested on Operator SDK 1.42 and kind.
Kubernetes Tutorial for Beginners & Experienced
Free Kubernetes tutorial from first cluster to Helm, RBAC, and upgrades, with hands-on lessons run on Kubernetes 1.36 kubeadm clusters, local and on AWS.
Golang Tutorial for Beginners (Hands-On)
Free Golang tutorial for beginners: 200+ runnable lessons on modules, structs, errors, goroutines, HTTP and gRPC APIs, databases, testing, and Docker.
Java Tutorial for Beginners (with examples)
Free Java tutorial for beginners: 100+ lessons on OOP, collections, lambdas, file I/O, exceptions, and multithreading, with examples run on OpenJDK 17.
Modern JavaScript Tutorial (ES6+ Hands-On)
Free JavaScript tutorial for beginners: 120+ runnable lessons on ES6+ syntax, arrays, objects, classes, async/await, the DOM, and common error fixes.
Node.js Tutorial for Beginners (Hands-On)
Free Node.js tutorial for beginners: 60 hands-on lessons on files, async code, HTTPS servers, Express, MongoDB, MySQL, Passport login, and deployment.
Python Tutorial for Beginners (Hands-On)
Free Python tutorial for beginners: 160+ hands-on lessons on data types, loops, OOP, file I/O, regex, concurrency, and Flask, tested on Python 3.13.
Podman Tutorial: Complete Container Guide for Linux
Free Podman tutorial tested on RHEL 10.2 with Podman 5.8: run rootless containers, build images, set up networking, and deploy services with Quadlet.
Git & GitHub Tutorial for Beginners (with examples)
Free Git and GitHub tutorial with hands-on examples tested on Git 2.52: commits, branches, merge and rebase, remotes, undo, and history cleanup.
Microsoft Azure Tutorial for Beginners (Hands-On)
Free hands-on Microsoft Azure tutorial for beginners: Entra ID, VMs, App Service, AKS, Blob Storage, VPN, Front Door, ARM templates, and cost control.
Ansible Tutorial for Beginners [RHCE EX294 Exam]
Free Ansible tutorial and Red Hat RHCE EX294 exam prep with hands-on labs on Rocky Linux 10: playbooks, roles, Vault, and RHCSA tasks automated end to end.
Keycloak IAM Tutorial: Identity and Access Management Course
Free Keycloak tutorial and IAM course covering realms, clients, OIDC, LDAP federation, SAML, and operations, with Podman labs tested on Keycloak 26.7.
389 Directory Server Tutorial: Complete Administration Guide
Free 389 Directory Server course: dscreate, dsconf and dsidm, TLS, ACIs, password policy, replication, and LMDB tuning, tested on 389-ds-base 3.2.
Keytool & Java Keystore Tutorial for Beginners
Free keytool tutorial for Java keystores and truststores: PKCS12, CSRs, chain imports, cacerts, PKIX fixes, and Spring Boot and Tomcat HTTPS on JDK 21.
OpenLDAP Tutorial for Beginners - Install, Configure, Replicate
Free OpenLDAP tutorial for Linux admins: cn=config and MDB, TLS, ACLs, password policy, SSSD clients, replication, and backup, tested on OpenLDAP 2.6.
OpenSSL & PKI Certificates Tutorial for Beginners
Free OpenSSL and PKI tutorial: generate keys and CSRs, build a root and intermediate CA, issue SAN certificates, set up mTLS, then renew and revoke.