Ravindra BagaleCourses & study guides

Quick-Revision Summary (All Chapters)

Chapter Must-remember points
1 Networking IP = host, port = service; 22/80/443/3306/27017/3000/5000/8080; IPv4 32-bit, CIDR 2^(32−n), AWS reserves 5/subnet; IPv6 128-bit, :: once; RFC 1918 private ranges; NAT; auto public IP vs Elastic IP
2 OSI 7 layers (Physical → Application), PDUs bit/frame/packet/segment/data; TCP/IP 4 layers; TCP vs UDP; DNS → TCP → TLS → HTTP
3 Linux basics ls cd cp mv rm mkdir cat less tail; chmod 755/​644/​400, chown; useradd, usermod -aG; apt vs yum; ps top kill; nano/vim
4 Linux advanced grep find awk sed; pipes/redirection/tee; tar; service (+ systemctl enable)/journalctl; ip ss curl dig; df du lsblk mount fstab; cron; env vars; ssh scp rsync; bash scripts
5 EC2 AMI + type + key pair + SG + EBS; pricing models; SSH users; chmod 400; PuTTY/.ppk, MobaXterm, OpenSSH; stop vs terminate; best practices
6 Web servers Nginx (event-driven, proxy) vs Apache (modules, .htaccess); httpd vs apache2; web roots; nginx -t; firewalld/SELinux on CentOS
7 Static hosting Files → /var/www/mysite → 755/644 → server block / vhost → test → reload; restorecon; 403/404 troubleshooting
8 Configuring web servers Port → site (Host header) → folder → file; conf.d vs sites-available; default_server / first vhost wins; change root + <Directory>; semanage fcontext/port; redirects, server_​tokens off; backup → test → reload → curl
9 Domains & DNS Registrar ≠ name servers ≠ web host; resolver → root → TLD → authoritative, TTL; A, CNAME (not apex), MX, TXT, NS; Elastic IP first; GoDaddy A @ → EIP, CNAME www; Route 53 hosted zone + NS; subdomain = record + vhost; dig/nslookup; certbot -d for each name
10 Dynamic hosting MariaDB/MySQL install & secure; app user; PHP-FPM; Flask + Gunicorn + systemd; Express + pm2; reverse proxy; 502 fixes
11 Apps WordPress full install; Flask with Gunicorn + Nginx; Express with pm2 cluster + Nginx
12 Stacks LAMP, LEMP, MEAN, MERN; MongoDB official repo; SPA build served by Nginx + /api proxy
13 EBS gp3/gp2/io2/st1/sc1; snapshots; NVMe names; grow: modify → growpart → xfs_growfs/resize2fs; add: attach → mkfs → mount → fstab UUID nofail; detach safely
14 EC2 operations Elastic IP: allocate → associate → re-associate → release (5/region, charged even idle); AMI = snapshots + block device mapping + permissions, create/launch/copy/share, deregister + delete snapshots, golden AMI; snapshot restore (ro,nouuid), DLM; change instance type: stop → change → start, verify nproc/free -h/lscpu

A Last Word from Ravindra

Shabbas, mitranno — you have reached the end of the handbook! Now the real learning starts: rebuild every lab on your own, without looking at the book, until it feels natural. Break things, fix them, and write down what you learnt. Keep practising, keep asking "why", and all the best for your projects and interviews. Chala, bhetuya pudhchya session madhe (let's meet in the next session)!

— Ravindra Bagale, Cloud Trainer · linkedin.com/in/ravindra-bagale