Networking

13. Networking#

Overview

Modern system administration and DevOps work heavily involve network operations: checking connectivity, transferring files, executing commands remotely, and monitoring network services. This chapter covers essential networking tools and techniques for shell scripting.

Topics:

  • Network diagnostics: ping, curl, wget

  • Secure file transfer: scp, rsync

  • Remote execution via SSH

  • Network automation and monitoring

  • Practical remote operations workflows

These skills are essential for:

  • Server administration and maintenance

  • Deployment automation

  • Data synchronization across systems

  • Infrastructure monitoring

  • Disaster recovery operations

What You'll Learn

By the end of this chapter, you will be able to:

✓ Test network connectivity and diagnose issues ✓ Transfer files securely between systems ✓ Execute commands remotely via SSH ✓ Automate remote operations and deployments ✓ Work with network services and APIs ✓ Synchronize data across systems ✓ Build infrastructure automation scripts ✓ Handle remote failures and recovery

Chapter Map

Section

Topic

Key Concepts

1302

Network Diagnostics

ping, nc, curl, network testing

1303

SSH & Remote Execution

SSH keys, remote commands, tunneling

1304

File Transfer

scp, rsync, secure synchronization

1305

API Integration

curl, jq, webhooks, JSON parsing

1306

Lab: Infrastructure Automation

Multi-server operations

Why This Matters

Network operations enable modern infrastructure automation:

  • Deployments: Automate application rollouts across servers

  • Data synchronization: Keep systems in sync

  • Monitoring: Aggregate metrics from multiple hosts

  • Disaster recovery: Automated failover and recovery

  • Cloud management: Manage multiple cloud instances

Real-world impact: A deployment script can update 100 servers in minutes without manual SSH sessions.

Prerequisites

You should already understand:

  • Bash scripting (Chapters 5-8)

  • Error handling (Chapter 11)

  • Basic networking (TCP/IP, ports, DNS)

  • SSH and basic Linux administration

What You'll Learn

By the end of this chapter, you will be able to:

✓ Test network connectivity and diagnose issues ✓ Transfer files securely between systems ✓ Execute commands remotely via SSH ✓ Automate remote operations and deployments ✓ Work with network services and APIs ✓ Synchronize data across systems ✓ Build infrastructure automation scripts ✓ Handle remote failures and recovery

Chapter Map

Section

Topic

Key Concepts

1302

Network Diagnostics

ping, nc, curl, network testing

1303

SSH & Remote Execution

SSH keys, remote commands, tunneling

1304

File Transfer

scp, rsync, secure synchronization

1305

API Integration

curl, jq, webhooks, JSON parsing

1306

Lab: Infrastructure Automation

Multi-server operations

Why This Matters

Network operations enable modern infrastructure automation:

  • Deployments: Automate application rollouts across servers

  • Data synchronization: Keep systems in sync

  • Monitoring: Aggregate metrics from multiple hosts

  • Disaster recovery: Automated failover and recovery

  • Cloud management: Manage multiple cloud instances

Real-world impact: A deployment script can update 100 servers in minutes without manual SSH sessions.

Prerequisites

You should already understand:

  • Bash scripting (Chapters 5-8)

  • Error handling (Chapter 11)

  • Basic networking (TCP/IP, ports, DNS)

  • SSH and basic Linux administration