Network Implementations represents the "how" of networking. While the OSI model teaches you the theory, this domain tests your ability to select, configure, and maintain the actual devices that move data. From configuring dynamic routing protocols like OSPF to setting up VLANs on a switch and securing a wireless network with WPA3, these skills are the bread and butter of a Network Administrator.
This guide covers the critical technologies you need for the N10-008 and N10-009 exams, broken down by device role and protocol function.
Routing Technologies
Static vs. Dynamic Routing
Routers need a map of the network (Routing Table) to know where to send packets. This map can be built in two ways:
- Static Routing: An administrator manually types in every route.
Pros: Secure, no CPU overhead. Cons: Does not adapt to outages; maintenance nightmare for large networks. - Dynamic Routing: Routers talk to each other using protocols to share network status.
Pros: Automatically routes around failures (convergence). Cons: Uses CPU/Bandwidth.
Common Dynamic Protocols
Interior Gateway Protocols (IGP)
Used within an organization (Autonomous System).
- OSPF (Open Shortest Path First): Link-state protocol. Uses "Cost" (bandwidth) as metric. Fast convergence. Most popular for enterprise LANs.
- EIGRP (Enhanced Interior Gateway Routing Protocol): Cisco proprietary (historically) "Advanced Distance Vector". Uses Bandwidth + Delay.
- RIP (Routing Information Protocol): Distance-vector. Uses "Hop Count" (max 15). Old and slow.
Exterior Gateway Protocols (EGP)
Used between organizations (Network to Network).
- BGP (Border Gateway Protocol): The protocol of the Internet. Path-vector. Slow convergence but massive scalability. Uses "Attributes" and policies to choose paths.
Bandwidth Management
Networks aren't infinite. We use tools to manage congestion:
- Traffic Shaping Buffering traffic to smooth out bursts, ensuring a consistent flow rate. Good for staying within ISP data caps.
- QoS (Quality of Service) Prioritizing specific traffic types. E.g., giving VoIP packets a "VIP pass" so phone calls don't drop when someone downloads a large file.
Switching Technologies
VLANs (Virtual LANs)
A VLAN logically separates a physical switch into multiple virtual switches. Even if computers are plugged into the same box, if they are in different VLANs, they cannot talk without a router (Inter-VLAN Routing).
- Security: Isolates sensitive departments (e.g., HR) from guests.
- Performance: Reduces broadcast traffic (Broadcast Domains).
- Organization: Groups users by function, not physical location.
802.1Q Trunking
When you need to carry multiple VLANs across a single cable between switches, you use a Trunk.
The 802.1Q standard adds a "Tag" to the Ethernet frame header, identifying which VLAN the packet belongs to.
STP (Spanning Tree)
Redundancy is good, but loops are deadly. If you plug two cables between switches, packets loop forever (Broadcast Storm).
802.1D STP detects loops and automatically blocks specific ports to create a loop-free tree topology. RSTP (802.1w) is the modern, faster version.
PoE (Power over Ethernet)
| Standard | Name | Max Power | Use Case |
|---|---|---|---|
| 802.3af | PoE | 15.4 W | IP Phones, Basic Cameras |
| 802.3at | PoE+ | 30 W | Wireless APs (Wi-Fi 5/6) |
| 802.3bt | PoE++ | 60W / 100W | PTZ Cameras, Laptops |
Wireless Standards
Wi-Fi Generations
- 802.11ac (Wi-Fi 5): 5GHz only. Introduced MU-MIMO (Downlink only). The standard for years.
- 802.11ax (Wi-Fi 6): 2.4GHz and 5GHz. Improved efficiency (OFDMA), bi-directional MU-MIMO. Better battery life for devices (Target Wake Time).
- Wi-Fi 6E: Everything in Wi-Fi 6, plus access to the massive 6GHz spectrum band (less interference).
Frequencies & Channels
- 2.4 GHz: Long range, penetrates walls well. High interference (microwaves, Bluetooth). Non-overlapping channels: 1, 6, 11.
- 5 GHz: Faster speeds, shorter range. Many more non-overlapping channels.
- Channel Bonding: Combining channels (e.g., 20MHz -> 40MHz -> 80MHz) to increase bandwidth.
Wireless Security
Never use WEP or WPA(TKIP). Always use:
- WPA2-AES: The minimum standard. Uses CCMP.
- WPA3: The new gold standard. Uses SAE (Simultaneous Authentication of Equals) to prevent dictionary attacks.
- Enterprise Mode (802.1X): Instead of everyone sharing one Wi-Fi password (PSK), users log in with their own username/password via a RADIUS server.
Ready to test your knowledge?
Implementations concepts like VLANs and Routing Protocols are heavy on the Network+ exam. Take our practice quiz to verify your skills.
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