🚀 Week 1 Report – Complete Networking for DevOps
Welcome to my Week 1 report of the #90DaysOfDevOps challenge.
This week was focused entirely on Networking Fundamentals, one of the most important skills for every DevOps Engineer. Before learning Docker, Kubernetes, CI/CD, Cloud, or Infrastructure as Code, understanding networking is essential because every service communicates through a network.
🌐 Why Networking is Important in DevOps
Most production issues are related to networking:
- DNS failures
- Port connectivity issues
- Load Balancer problems
- Firewall restrictions
- SSL/TLS certificate issues
- Kubernetes networking problems
- Cloud VPC misconfigurations
A DevOps Engineer spends a lot of time troubleshooting communication between services.
Understanding networking helps identify issues quickly and maintain reliable infrastructure. Many DevOps practitioners emphasize that networking fundamentals are critical for debugging cloud, Kubernetes, and infrastructure problems.
📚 OSI Model
The OSI (Open Systems Interconnection) Model explains how data travels across a network.
| Layer | Name |
|---|---|
| 7 | Application |
| 6 | Presentation |
| 5 | Session |
| 4 | Transport |
| 3 | Network |
| 2 | Data Link |
| 1 | Physical |
Physical Layer
Responsible for transmitting bits through cables and signals.
Examples:
- Ethernet
- Fiber Optics
- Wireless Signals
Data Link Layer
Responsible for:
- MAC Addressing
- Error Detection
- Frame Transmission
Device:
- Switch
Network Layer
Responsible for:
- IP Addressing
- Routing
- Packet Delivery
Device:
- Router
Transport Layer
Provides end-to-end communication.
Protocols:
- TCP
- UDP
Functions:
- Segmentation
- Error Recovery
- Flow Control
Session Layer
Responsible for:
- Session Creation
- Session Management
- Session Termination
Presentation Layer
Responsible for:
- Encryption
- Compression
- Data Formatting
Application Layer
Closest layer to the user.
Examples:
- HTTP
- HTTPS
- DNS
- FTP
- SSH
🌍 TCP/IP Model
The TCP/IP Model is the practical implementation used on the Internet.
| Layer | Function |
|---|---|
| Application | User Services |
| Transport | Communication |
| Internet | Routing |
| Network Access | Physical Network Access |
Networking for DevOps is usually discussed using the TCP/IP model because it reflects real-world Internet communication.
🔄 OSI vs TCP/IP
| OSI | TCP/IP |
|---|---|
| 7 Layers | 4 Layers |
| Theoretical Model | Practical Model |
| Developed by ISO | Developed by DARPA |
🌐 IP Addressing
Every device on a network requires an IP Address.
Example:
192.168.1.10
Types:
Public IP
Accessible from the Internet.
Example:
8.8.8.8
Private IP
Used inside internal networks.
Examples:
- 192.168.x.x
- 172.16.x.x – 172.31.x.x
- 10.x.x.x
📦 Subnetting
Subnetting divides a large network into smaller networks.
Example:
192.168.1.0/24
Benefits:
- Better Security
- Better Network Management
- Reduced Traffic
Subnetting and CIDR notation are foundational networking concepts used heavily in cloud environments and DevOps infrastructure.
🔢 CIDR Notation
CIDR = Classless Inter-Domain Routing
Examples:
- /24 = 255.255.255.0
- /16 = 255.255.0.0
- /32 = Single Host
Example:
192.168.1.0/24
🔐 Common Networking Protocols
HTTP
Used for web communication.
Port:
80
Example:
HTTPS
Secure version of HTTP.
Port:
443
Provides:
- Encryption
- Security
- Data Integrity
DNS
Domain Name System converts domain names into IP addresses.
Example:
google.com → IP Address
Without DNS, users would need to remember IP addresses.
DNS is consistently identified as one of the most important networking concepts for DevOps engineers.
SSH
Secure Shell is used for remote server access.
Port:
22
Example:
ssh user@server-ip
This is one of the most frequently used protocols in DevOps.
FTP
Used for file transfers.
Default Port:
21
SMTP
Used for sending emails.
⚡ TCP vs UDP
| Feature | TCP | UDP |
|---|---|---|
| Connection | Yes | No |
| Reliability | High | Low |
| Speed | Slower | Faster |
| Error Checking | Yes | Minimal |
TCP Examples
- HTTP
- HTTPS
- SSH
- FTP
UDP Examples
- Gaming
- Video Streaming
- VoIP
Understanding TCP and UDP is considered a core networking requirement for DevOps professionals.
🔥 Ports Every DevOps Engineer Should Know
| Service | Port |
|---|---|
| HTTP | 80 |
| HTTPS | 443 |
| SSH | 22 |
| FTP | 21 |
| SMTP | 25 |
| DNS | 53 |
| MySQL | 3306 |
| PostgreSQL | 5432 |
| Jenkins | 8080 |
| Kubernetes API | 6443 |
🛡️ Firewalls
Firewalls control incoming and outgoing network traffic.
Examples:
- AWS Security Groups
- NACLs
- Linux UFW
- iptables
Purpose:
- Security
- Access Control
- Traffic Filtering
⚖️ Load Balancers
Load Balancers distribute traffic across multiple servers.
Benefits:
- High Availability
- Scalability
- Fault Tolerance
Examples:
- NGINX
- HAProxy
- AWS ALB
- AWS NLB
Load balancing and reverse proxies are commonly cited as networking concepts DevOps engineers should understand.
☁️ Networking in Cloud Computing
Cloud networking includes:
- VPC
- Subnets
- Route Tables
- NAT Gateway
- Internet Gateway
- Security Groups
Without networking knowledge, cloud architecture becomes difficult to understand.
☸️ Networking in Kubernetes
Networking is heavily used in Kubernetes:
- Pods
- Services
- ClusterIP
- NodePort
- Ingress
- Network Policies
Most Kubernetes communication depends on networking concepts.
🛠 Essential Networking Commands for DevOps
Check IP Address
ip addr
Check Connectivity
ping google.com
DNS Lookup
nslookup google.com
or
dig google.com
Check Open Ports
ss -tulpn
Trace Route
traceroute google.com
Test HTTP Response
curl -I https://google.com
Real-world DevOps troubleshooting often relies on commands like ping, dig, traceroute, curl, and port inspection tools.
🎯 Key Learnings From Week 1
✅ OSI Model
✅ TCP/IP Model
✅ IP Addressing
✅ Subnetting
✅ CIDR
✅ DNS
✅ HTTP/HTTPS
✅ SSH
✅ TCP vs UDP
✅ Firewalls
✅ Load Balancers
✅ Cloud Networking Basics
✅ Kubernetes Networking Basics
✅ Networking Troubleshooting Commands
🚀 Conclusion
Networking is not just another topic in DevOps.
It is the foundation behind cloud platforms, Linux servers, Docker containers, Kubernetes clusters, CI/CD pipelines, APIs, and distributed applications.
This week helped me understand how systems communicate, how requests travel across networks, and how DevOps engineers troubleshoot real-world infrastructure issues.
The stronger your networking fundamentals are, the easier it becomes to learn Cloud, Kubernetes, Security, and Site Reliability Engineering.
Thank you for reading my Week 1 report.
Happy Learning! 🚀
Top comments (0)