Day 67 of 90 Days of DevOps Challenge: Networking for DevOps - IP address & MAC address

As I near the completion of my 90 Days of DevOps Challenge, today marks a significant checkpoint. I've wrapped up my learning on Ansible, a tool that gave me the power to automate infrastructure, configurations, and deployments with ease.

Over the past 66 days, I’ve explored and practiced:

• Linux & Shell Scripting: mastering the core of system operations.

• Git, GitHub, GitLab, Bitbucket: for version control and collaboration.

• Maven, Tomcat: understanding Java-based application builds and deployments.

• Docker & Kubernetes: containerization and orchestration at scale.

• Terraform: Infrastructure as Code to automate cloud infrastructure.

• Ansible: Configuration Management and Automation.

• Jenkins: CI/CD pipelines for continuous delivery.

• Monitoring & Observability with Prometheus & Grafana.

These tools together formed a strong DevOps foundation. Now, it’s time to expand that foundation further.

I’m transitioning into the AWS Cloud ecosystem diving deep into cloud services, deployments, networking, and scalable infrastructure in AWS. Cloud skills are critical for modern DevOps, and I’m excited to take that on in the remaining days of this challenge.

A solid understanding of networking is essential for any DevOps Engineer. Today, I revisited key networking fundamentals, focusing on IP address and MAC address.

What is an IP Address?

An IP Address (Internet Protocol Address) is a unique identifier assigned to each device connected to a network. It enables devices to communicate over the internet or private networks.

IP Address Versions

IPv4:

• Written in decimal format divided into four octets, separated by dots.

• Format: 192.168.0.1

• 32-bit, approximately 4.3 billion unique addresses.

• Limited address space.

• No built-in security or encryption.

IPv6:

• Written in hexadecimal format separated by colons.

• Format: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

• 128-bit, designed to provide an almost infinite number of addresses.

• Built-in security: IPsec is natively supported.

• Better routing efficiency and performance.

IP Address Classes (IPv4)

NOTE: Today, Classes D & E are used less frequently, but it's useful to understand them historically.

Static vs Dynamic IP

Static IP:

A Static IP address is manually configured and does not change over time. The device retains the same IP every time it connects to the network. Common for servers, VPNs, and databases.

Advantages

• Reliable for hosting services.

• Easier for DNS mapping (domain to IP).

• Simplifies remote access.

Disadvantages

• Less flexible in large networks.

• Higher risk of being targeted by malicious actors.

• May incur additional costs (e.g., AWS Elastic IP if not attached).

Dynamic IP:

Assigned by DHCP (Dynamic Host Configuration Protocol), changing over time. Common for home users and general devices.

Advantages

• Efficient use of limited IP address space.

• Less management overhead.

• Often free in cloud platforms.

Disadvantages

• IP can change, so unsuitable for hosting services without additional DNS handling.

• May complicate remote access setups.

Public vs Private IP

• Public IP:

  • Routable over the internet.

  • Unique globally.

  • Example: 8.8.8.8 (Google DNS)

• Private IP:

  • Used within internal networks.

  • Not routable publicly.

  • Example Ranges:

    • Class A: 10.0.0.0 – 10.255.255.255

    • Class B: 172.16.0.0 – 172.31.255.255

    • Class C: 192.168.0.0 – 192.168.255.255

NOTE: Private IP addresses need NAT (Network Address Translation) to access the internet.

Loopback IP Address

• 127.0.0.1 is the standard loopback address.

• It is used to test network interfaces on the local machine itself.

• Example: ping 127.0.0.1 tests if TCP/IP stack is functioning.

MAC Address (Media Access Control Address)

• A hardware identifier that uniquely identifies each device on a network.

• Format: 00:1A:2B:3C:4D:5E

• It operates at the Data Link Layer (Layer 2 of OSI model).

• Immutable and set by hardware manufacturers.

NOTE: MAC addresses help in network traffic management at the hardware level (e.g., switches).

Final Thoughts

Understanding networking is indispensable for DevOps professionals. Whether deploying a Kubernetes cluster on AWS or configuring a CI/CD pipeline, networking knowledge ensures seamless infrastructure communication, secure access, and optimized performance.

Today’s exploration of IP addresses, their classifications, and how networking elements work sets a strong base for the AWS networking concepts I’ll tackle next like VPCs, Subnets, Route Tables, and Security Groups.

As I wrap up my Ansible learning, I’m enthusiastic about scaling this knowledge into cloud deployments, where networking + cloud + automation converge to form the backbone of modern DevOps.