MODULE 4: Networking for IT Support
This module teaches the networking skills every IT Support Technician must know.
In real offices, the most common complaint is:
❝ The internet is not working ❞
By the end of this module, students will be able to understand basic networking, connect systems to LAN & Wi-Fi, and troubleshoot most everyday network problems confidently.
What You Will Learn in This Module
By the end of Module 4, you will be able to:
- Understand how computers communicate on a network
- Explain IP address, DNS, DHCP, Gateway in simple terms
- Connect and troubleshoot LAN & Wi-Fi
- Identify and fix common internet & network issues
- Perform basic router, switch & access point tasks
- Use basic network troubleshooting commands
Lesson 1: What is a Computer Network?
Definition
A computer network is a group of devices connected together to share data, internet, and resources.
Examples of shared resources:
- Internet connection
- Printers
- Files & folders
- Servers
Why Networking Is Important for IT Support
Without networking:
- No internet
- No email
- No shared printers
- No file sharing
- No cloud access
Types of Networks (Simple)
- LAN (Local Area Network) → Office, school, home
- MAN (Metropolitan Area Network) → City-wide
- WAN (Wide Area Network) → Internet
As IT support, LAN & internet access are your daily responsibility.
Lesson 2: IP Address, DNS, DHCP & Gateway (In Simple Terms)
This lesson explains the four most important networking concepts for IT Support.
- IP Address — Device Identity
An IP address is like a phone number for a computer.
Examples:
- 192.168.1.10
- 10.0.0.5
Every device on a network must have a unique IP.
- DNS — Internet Phonebook
DNS converts:
google.com → 142.250.190.78
Without DNS:
- Internet will not work using website names
- Only IPs will work
- DHCP — Automatic IP Giver
DHCP automatically assigns:
- IP address
- Subnet mask
- Gateway
- DNS
Without DHCP:
- Devices must be configured manually
- Network problems increase
- Default Gateway — Exit Door to Internet
The gateway is the router address.
If gateway fails:
- Local network may work
- Internet will NOT work
Lesson 3: Essential Networking Devices for IT Support
- Router
- Connects LAN to the internet
- Assigns IP addresses (DHCP)
- Performs NAT
- Controls firewall (basic level)
- Switch
- Connects multiple wired devices inside the LAN
- Expands network ports
- Faster than hubs
- Access Point (AP)
- Provides Wi-Fi
- Connects wireless devices to the LAN
- Modem
- Connects ISP line to router
- Converts ISP signal into usable internet
Lesson 4: Wired Networking (LAN & Ethernet)
Ethernet Cable Types
- Cat5e
- Cat6
- Cat6a
Wired Network Advantages
- Faster speed
- More stable
- Less interference
- Better for:
-
- Offices
- Servers
- Printers
Common Wired Network Problems
| Problem | Possible Cause |
| No internet | Bad cable / wrong IP |
| Limited access | DHCP issue |
| Network disconnects | Loose port |
| Slow speed | Bad switch port |
Lesson 5: Wireless Networking (Wi-Fi Basics)
Wi-Fi Bands
- 2.4 GHz → Longer range, slower
- 5 GHz → Fast speed, short range
Wi-Fi Security Types
- WPA2
- WPA3
(Always recommended)
Common Wi-Fi Problems
- Weak signal
- Interference
- Wrong password
- Too many clients
- Old router firmware
Lesson 6: Basic Router Configuration (IT Support Level)
IT support level tasks include:
- Changing Wi-Fi name (SSID)
- Changing Wi-Fi password
- Rebooting router
- Checking connected devices
- Enabling/disabling DHCP
- MAC filtering (basic understanding)
Lesson 7: Essential Network Troubleshooting Commands
These commands help diagnose network issues fast:
| Command | Purpose |
| ipconfig | Shows IP details |
| ping | Checks connectivity |
| tracert | Shows route to a site |
| nslookup | Tests DNS |
| netstat | Shows network connections |
Lesson 8: Common Network Problems & Practical Fixes
| User Complaint | Likely Cause | IT Support Action |
| “No internet” | Wrong IP / DNS | ipconfig / renew |
| “Wi-Fi connected but no internet” | Gateway issue | Restart router |
| “Printer not found” | Wrong network | Check IP subnet |
| “Slow internet” | Heavy download | Limit usage |
| “Only one PC has no internet” | Driver issue | Reinstall driver |
Lesson 9: Simple Network Security for IT Support
IT Support must enforce:
- Strong Wi-Fi passwords
- Disable unknown devices
- Change default router passwords
- Update router firmware
- Avoid open public Wi-Fi
- Block unauthorized access when noticed
This supports cybersecurity at the support level.
MODULE 4 SUMMARIES
By completing Module 4, students now understand:
- How basic networking works
- How IP, DNS, DHCP & Gateway function
- How to set up wired & wireless networks
- How routers, switches & access points work
- How to troubleshoot common internet issues
- How to use network commands
- How to apply basic network security
This module answers the critical IT Support question:
“Why is the internet not working, and how do I fix it?”