Deepak Prasad

The "Cannot Assign Requested Address" error is quiet common in the network community and can be seen in various network-related and application specific

The "SSH: No route to host" error to be honest can occur n number of issues. There is no specific one solution which will work for all scenarios. So in this

DNS reconnaissance is a technique to gather information about DNS (Domain Name System) data. This process helps in identifying the network infrastructure and

Common active reconnaissance methods include the following:

Install Caddy on Ubuntu from the official Cloudsmith APT repo: add the GPG key, apt install caddy 2.11.4, verify systemd, serve a static site with a Caddyfile, open UFW ports 80 and 443, and enable automatic HTTPS for …

Explore solutions to the Docker error 'can only create exec sessions on running containers: container state improper.

Learn how to keep a Docker container running using multiple methods like TTY mode, entrypoint, sleep infinity, and process management. Fix containers exiting immediately with practical examples and best practices.

Learn how to override Docker ENTRYPOINT and CMD using docker run options. Understand the difference between ENTRYPOINT and CMD with practical examples and best practices.

Learn how to use docker ps -a to list all containers including stopped ones. Explore examples, filters, and output details to manage Docker containers effectively.

There are 3 different possible methods to perform docker container SSH. Using docker exec, docker attach and by running a SSHD service inside a container and using SSH client to connect to container

Docker restart container using various flags to control the restart behavior of the container

handle different condition in dockerfile such as docker file if else condition, arg conditions, ARG vs ENV comparison with examples

Learn what a URL fuzzer does, how web application fuzzing works, when to use online URL fuzzers vs command-line tools, and how to choose between FFUF, Gobuster, Dirsearch, Wfuzz, Feroxbuster, and Burp Intruder for …

Learn practical and authorized ways to find hidden API endpoints using browser DevTools, JavaScript files, GitHub search, archived URLs, gau/getallurls, APK analysis, and JS recon tools such as LinkFinder and JSFScan.

Use nmap, hping3 and netcat (nc) to check open ports in Linux. You can also use netcat to test firewall rules to make sure if a port is open or closed in a network.

Kubernetes Helm Charts are package manager used to deploy charts (package). This can contain all type of resources and deploy or un-deploy them instantly. It makes handling complex applications very easy.

How to create shared folder using Oracle VirtualBox with Linux Operating System? Can I share a folder from Windows host to Linux OS inside Oracle Virtual Box?

Tutorial Manage Docker Container. Download Docker Image from Docker Hub. How to connect and exit from docker container query docker hub and check logs

Install jq on Ubuntu with sudo apt install jq, verify with jq --version, pretty-print and filter JSON from files and curl output, fix Unable to locate package jq with apt update, and optionally install jq 1.8.x from …

Install zlib on Ubuntu with sudo apt install zlib1g-dev for headers and pkg-config, fix configure could not find the zlib library and zlib.h not found errors, verify with pkg-config --modversion zlib, and optionally …

Install NVM on Ubuntu with the official install.sh script, load it in bash or zsh, install LTS Node.js with nvm install --lts, switch versions with nvm use, set a default alias, and fix nvm command not found and Snap …

Install HPLIP on Ubuntu with sudo apt install hplip hplip-gui for most HP printers, use HP SourceForge .run when your model needs a newer driver, run hp-plugin and hp-setup to add the device, and remove conflicts before …

Install Kali Linux tools on Ubuntu with sudo apt install for nmap, sqlmap, nikto, and other hacking tools in Ubuntu repositories. Use Snap when apt has no package. Katoolin is legacy on modern Ubuntu—use a Kali VM when …

Repair Debian after a power outage using a symptom-first decision tree: fix emergency mode and fstab, run fsck on unmounted ext4, reinstall GRUB on BIOS or UEFI, rebuild initramfs, recover interrupted apt/dpkg, and know …

Install Grafana on Ubuntu 25.04 from the official apt.grafana.com repository or a .deb package: import the GPG key, enable grafana-server, open port 3000, log in as admin, and verify with curl and /api/health.

Install XCP-ng guest tools on Ubuntu with apt install xe-guest-utilities or the guest-tools ISO from Xen Orchestra; enable xe-daemon, verify management agent detection, and use the ISO when apt lags behind XCP-ng.

Install qbittorrent-nox on Ubuntu from the official PPA or universe repo, accept the legal notice, log in to the Web UI, run it under a dedicated user with the bundled systemd template, open the firewall safely, and fix …

Install Telegram Desktop on Ubuntu with Snap, the official tsetup Linux tarball from desktop.telegram.org, or Flatpak: verify version 6.9.3, launch from the app menu, update with snap refresh, and uninstall cleanly.

C and C++ interview questions and answers for {year}: C pointers and memory, C++ OOP, RAII, smart pointers, STL, move semantics, coding problems, and systems prep.

TypeScript and interview questions on TypeScript for {year}: types, generics, utility types, narrowing, satisfies, strict mode, React/Node prep with elaborate answers.