200-301 - Network Fundamentals (20% of the exam) - Section 1.1
Explain the role and function of network components - routers, Layer 2 and Layer 3 switches, next-generation firewalls and IPS, access points, controllers, endpoints, servers, and PoE - and characterise topology architectures.
Identify what each device in a campus network does: routers move packets between subnets, Layer 2 switches forward frames within a VLAN, Layer 3 switches add inter-VLAN routing, and wireless LAN controllers manage lightweight access points. Distinguish two-tier and three-tier campus designs, spine-leaf, WAN, and SOHO topologies, and recognise on-premise versus cloud placement of network services.
Network componentsLayer 2 vs Layer 3 switchWLAN controllerTwo-tier and three-tier architecturePoE
Practice question for this objective
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A campus needs a single device that forwards frames between hosts in the same VLAN and also moves traffic between separate IP subnets at wire speed without a separate router. Which statement correctly distinguishes a Layer 3 switch from a Layer 2 switch in this role?
AA Layer 2 switch can route between IP subnets in hardware, whereas a Layer 3 switch only floods broadcasts within one VLAN.
BBoth switches forward strictly on destination MAC address, and neither can move traffic between separate IP subnets without an external router.
CA Layer 3 switch can forward between IP subnets using routing in hardware, whereas a Layer 2 switch only forwards within a VLAN based on MAC addresses.check_circle Correct
DA Layer 2 switch makes forwarding decisions on destination IP address, whereas a Layer 3 switch makes them on destination MAC address.
Distinguish a Layer 3 switch, which routes between IP subnets in hardware, from a Layer 2 switch, which forwards within a VLAN by MAC address. A Layer 2 switch builds a MAC address table and forwards frames within a single broadcast domain, while a Layer 3 switch adds a routing function in ASIC hardware so it can forward packets between different IP subnets at high speed without relying on a separate router.
Why A is wrong: This reverses the two devices: routing between subnets is the Layer 3 switch capability, and confining traffic to a single VLAN is the Layer 2 behaviour, so the roles are swapped and the statement is wrong.
Why B is wrong: It is true that a Layer 2 switch needs an external router, but a Layer 3 switch can route between subnets itself; claiming neither device can is incorrect and ignores the defining Layer 3 capability.
Why C is correct: A Layer 3 switch combines switching with hardware routing so it can move packets between subnets, while a Layer 2 switch makes forwarding decisions solely on destination MAC addresses inside a single VLAN, which is exactly the distinction the scenario needs.
Why D is wrong: A Layer 2 switch forwards on MAC, not IP, and a Layer 3 switch adds IP-based routing rather than dropping to MAC-only; the two criteria are attached to the wrong devices, so the statement is false.
Answers that look right on this material and are not. Each one is a distractor from a different question in the 200-301 bank for this domain.
The two VLANs share one broadcast domain, so the hosts should reach each other directly once the trunk is allowed.
errorWhy it is wrong: Each VLAN is its own broadcast domain and its own subnet; allowing the trunk does not merge them, and crossing between subnets still needs a Layer 3 hop, so this does not solve the problem.
A next-generation firewall, which inspects application traffic and enforces security policy at the network edge.
errorWhy it is wrong: A next-generation firewall does enforce policy and inspect traffic, but it has no role in managing access point radios, wireless client authentication, or roaming, so it cannot perform the central wireless function described.
It supplies inline electrical power to the access points so that no separate power injector is required
errorWhy it is wrong: Inline power to an AP comes from a PoE switch port or a power injector, not from the controller; this confuses the controller with the device that energises the AP.