CCNA 200-301 v1.1 reference — Network Fundamentals
Network components
What routers, Layer 2 and Layer 3 switches, next-generation firewalls, access points, controllers, endpoints, servers and PoE each do in an enterprise network.
Objective 1.1v1.1 exam target
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Device roles at a glance
Router
Forwards packets between different IP networks
Maintains a routing table; each interface is a separate broadcast domain.
Layer 2 switch
Forwards Ethernet frames by MAC address
Learns source MACs per port; forwards, floods, or filters frames.
Layer 3 switch
Switch hardware that also routes
Uses SVIs and routed ports to route between VLANs at wire speed.
Access point
Bridges wireless clients to the wired LAN
Converts 802.11 frames to 802.3 Ethernet; one BSS per radio/SSID.
Controller
Central management for APs or the fabric
A WLC manages lightweight APs; Cisco DNA Center manages the fabric.
Network components and their function
| Component | Primary function | Operates mainly at | Typical placement |
|---|---|---|---|
| Router | Selects paths and forwards packets between IP networks | Layer 3 | WAN edge, between subnets, internet edge |
| L2 switch | Forwards frames between ports using the MAC table | Layer 2 | Access/distribution inside a LAN |
| L3 switch | Combines switching with inter-VLAN routing | Layers 2–3 | Distribution/core of a campus LAN |
| NGFW / IPS | Filters traffic using application and threat context | Layers 3–7 | Trust boundary, internet edge, DC edge |
| Access point | Associates wireless clients and bridges to Ethernet | Layer 2 (802.11 ↔ 802.3) | Ceilings/walls across the coverage area |
| WLC / controller | Centralizes AP config, RF management and roaming | Control/management plane | Data center or cloud |
| Endpoint | Originates and consumes traffic | All layers (host stack) | Desktops, phones, IoT devices |
| Server | Provides services to endpoints | All layers (host stack) | Data center, server room, cloud |
PoE standards and power budgets
| Standard | Common name | PSE output | PD receives | Pairs used |
|---|---|---|---|---|
| 802.3af | PoE | 15.4 W | 12.95 W | 2 pairs |
| 802.3at | PoE+ | 30 W | 25.5 W | 2 pairs |
| 802.3bt Type 3 | PoE++ / UPoE (Cisco proprietary name) | 60 W | 51 W | 4 pairs |
| 802.3bt Type 4 | PoE++ / UPoE | 90 W | 71.3 W | 4 pairs |
Related resources
Sources
- Cisco CCNA 200-301 v1.1 Exam Topics (official PDF) — reviewed 2026-11-02
Targets CCNA 200-301 v1.1 objectives. Supplemental blocks are labeled beyond exam scope.