Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2InfrastructureMedium
A network engineer is configuring a new Cisco Catalyst 9300 switch. The switch needs to support multiple VLANs and ensure that all inter-VLAN routing is performed efficiently in hardware. Which technology is crucial for achieving high-performance inter-VLAN routing on this switch?
- AHot Standby Router Protocol (HSRP)
- BSpanning Tree Protocol (STP)
- CCisco Express Forwarding (CEF)
- DVLAN Trunking Protocol (VTP)
Show answer & explanationAnswer & explanation
Correct answer: C. Cisco Express Forwarding (CEF)
Cisco Express Forwarding (CEF) is an advanced Layer 3 IP switching technology that enables faster packet forwarding by storing forwarding information (FIB) and adjacency tables in hardware (ASICs), significantly improving inter-VLAN routing performance.
Why the other options are wrong
- A. HSRP provides default gateway redundancy and does not directly enhance the forwarding performance of a single switch.
- B. STP prevents loops in Layer 2 networks and is not directly related to Layer 3 routing performance.
- D. VTP is used for managing VLAN configurations across switches and does not impact routing performance.
Cisco Express Forwarding (CEF)
A high-performance, distributed Layer 3 IP switching technology used on Cisco devices to accelerate packet forwarding.
- Stores forwarding information (FIB) and adjacency tables in hardware.
- Eliminates the need for per-packet route lookups.
- Crucial for efficient inter-VLAN routing and overall router/switch performance.
Memory trick: CEF is the fast track for packets, bypassing the slow lane.