Network Configuration & Internet Connections
Key Takeaways
- Static IP addresses are manually configured and do not change — used for servers, printers, and network infrastructure that must have consistent addresses.
- NAT (Network Address Translation) allows multiple devices with private IP addresses to share a single public IP address for internet access.
- A VPN (Virtual Private Network) creates an encrypted tunnel over the internet, allowing remote workers to securely access corporate network resources.
- Common internet connection types include cable (DOCSIS), DSL, fiber optic, satellite, cellular (4G/5G), and fixed wireless — each with different speed, latency, and availability characteristics.
- DNS settings can be changed from ISP defaults to public DNS services (Google: 8.8.8.8, Cloudflare: 1.1.1.1) for potentially faster resolution and better privacy.
Last updated: March 2026
Network Configuration & Internet Connections
Static vs. Dynamic IP Addressing
Dynamic (DHCP) — Most Common
- IP address is automatically assigned by a DHCP server
- Address may change each time the lease expires and renews
- Ideal for client devices (desktops, laptops, phones)
- Reduces administrative overhead — no manual configuration needed
Static — Manual Configuration
- IP address is manually configured and never changes
- Used for devices that must be consistently reachable:
- Servers (web, email, file, print)
- Network printers
- Routers and switches
- DNS and DHCP servers
- Requires configuring: IP address, subnet mask, default gateway, and DNS servers
DHCP Reservation (Best of Both)
- DHCP server always assigns the same IP address to a specific device (by MAC address)
- Device still uses DHCP (automatic) but gets a consistent address
- Ideal for printers and shared resources that need predictable addresses without manual configuration
NAT (Network Address Translation)
NAT allows multiple devices on a private network to share a single public IP address:
| NAT Type | Description | Use Case |
|---|---|---|
| Static NAT | One-to-one mapping (1 private ↔ 1 public) | Servers that need direct public access |
| Dynamic NAT | Pool of public IPs shared among private devices | Organizations with multiple public IPs |
| PAT (Port Address Translation) | Many private IPs share 1 public IP (different ports) | Home/SOHO networks (most common) |
PAT is also called NAT overload and is the most common form. Your home router uses PAT — all devices in your house share one public IP address, differentiated by port numbers.
VPN (Virtual Private Network)
A VPN creates an encrypted tunnel through the internet:
| VPN Type | Description | Use Case |
|---|---|---|
| Site-to-Site | Connects two entire networks over the internet | Branch offices to headquarters |
| Remote Access (Client-to-Site) | Individual user connects to corporate network | Remote workers, telecommuting |
| Split Tunnel | Only corporate traffic goes through VPN; internet traffic is direct | Reduces VPN bandwidth load |
| Full Tunnel | ALL traffic goes through VPN | Maximum security, all traffic inspected |
Common VPN Protocols:
- IPSec — Industry standard, works at Layer 3
- SSL/TLS VPN — Works through web browsers (port 443)
- WireGuard — Modern, lightweight, fast
- OpenVPN — Open-source, highly configurable
Internet Connection Types
| Connection | Download Speed | Upload Speed | Latency | Availability |
|---|---|---|---|---|
| Cable (DOCSIS 3.1) | 100 Mbps – 1 Gbps | 10–50 Mbps | 15–30ms | Suburban/urban |
| DSL (VDSL2) | 25–100 Mbps | 5–15 Mbps | 20–40ms | Wide (phone lines) |
| Fiber (FTTH) | 100 Mbps – 10 Gbps | 100 Mbps – 10 Gbps | 1–5ms | Growing, mainly urban |
| Satellite (LEO) | 50–200 Mbps | 10–30 Mbps | 20–40ms | Global (Starlink) |
| Satellite (GEO) | 12–100 Mbps | 3–5 Mbps | 500–700ms | Global (legacy) |
| Cellular (5G) | 100 Mbps – 1 Gbps | 30–100 Mbps | 10–30ms | Urban/suburban |
| Cellular (4G LTE) | 10–50 Mbps | 5–15 Mbps | 30–50ms | Wide |
| Fixed Wireless | 25–1000 Mbps | 5–100 Mbps | 10–30ms | Rural/suburban |
Exam Tip: Satellite (GEO) internet has very high latency (500-700ms) due to the distance signals must travel to geostationary orbit — this makes it unsuitable for real-time applications like VoIP and video conferencing.
Proxy Servers
A proxy server acts as an intermediary between clients and the internet:
| Proxy Type | Function |
|---|---|
| Forward Proxy | Client → Proxy → Internet (hides client identity, content filtering) |
| Reverse Proxy | Internet → Proxy → Server (load balancing, caching, security) |
| Transparent Proxy | Intercepts traffic without client configuration (often for content filtering) |
Benefits: Content caching, access control, bandwidth management, anonymity, logging
Common Network Configuration Commands
| Command | OS | Purpose |
|---|---|---|
| ipconfig | Windows | Display IP configuration |
| ipconfig /all | Windows | Display detailed IP configuration (MAC, DHCP, DNS) |
| ipconfig /release | Windows | Release current DHCP lease |
| ipconfig /renew | Windows | Request a new DHCP lease |
| ipconfig /flushdns | Windows | Clear the DNS resolver cache |
| ifconfig | Linux/macOS (legacy) | Display IP configuration |
| ip addr | Linux (modern) | Display IP configuration |
| ping | All | Test connectivity to a host |
| tracert / traceroute | Windows / Linux | Trace the route to a host |
| nslookup | All | Query DNS records |
| netstat | All | Display active network connections |
| nbtstat | Windows | Display NetBIOS statistics |
| pathping | Windows | Combines ping and tracert functionality |
Test Your Knowledge
What type of NAT allows multiple private IP addresses to share a single public IP address using different port numbers?
A
B
C
D
Test Your Knowledge
Which Windows command releases the current DHCP-assigned IP address?
A
B
C
D
Test Your Knowledge
Which internet connection type has the HIGHEST latency, making it unsuitable for real-time applications?
A
B
C
D
Test Your KnowledgeFill in the Blank
The Windows command used to clear the local DNS cache is: ipconfig /_______
Type your answer below