Layer 3 Switches vs Traditional Routers | Generated by AI
Question: What is the main difference between Layer 3 switches and traditional routers?
- Layer 3 switches differ from traditional routers mainly because they:
A) Use hardware-based fast forwarding for routing
B) Only support static routing
C) Cannot perform NAT
D) Operate only at Layer 2
Correct answer: A
Answer:
The primary difference between Layer 3 switches and traditional routers lies in their forwarding mechanisms.
Layer 3 switches perform inter-VLAN routing and IP forwarding using specialized hardware (typically ASICs - Application-Specific Integrated Circuits), enabling wire-speed routing performance with very low latency. This hardware-based forwarding (often called “route once, switch many” using CEF-like tables) makes them significantly faster than traditional routers for high-volume intra-network traffic.
Traditional routers, especially software-based ones, traditionally rely on CPU-processed routing decisions for each packet, which is slower compared to hardware acceleration.
Other options explained:
- B) Only support static routing: Incorrect. Modern Layer 3 switches support dynamic routing protocols (OSPF, EIGRP, RIP, BGP in some cases).
- C) Cannot perform NAT: While basic Layer 3 switches often lack full NAT capabilities (common in enterprise access/distribution layers), many higher-end models do support NAT. This is not the main difference.
- D) Operate only at Layer 2: Incorrect. Layer 3 switches operate at both Layer 2 (switching) and Layer 3 (routing).
Thus, the key distinguishing feature is hardware-based fast forwarding for routing, making option A the correct choice.