Questions
1. Which mechanism is the slowest method for switching packets, where every packet is
inspected by the switch CPU?
A. Cisco Express Forwarding
B. Fast Switching
C. Process Switching
D. Slow Switching
2. Which switching mechanism is the default method in most modern Cisco IOS devices?
A. Fast Switching
B. Cisco Express Forwarding
C. Process Switching
D. Slow Switching
3. Which memory architecture is used on all Catalyst switch models to perform Layer 2
switching?
A. CAM
B. TCAM
C. FIB
D. RIB
4. Which switch structure stores IP routing-related information, and is also referred to as the
Cisco Express Forwarding (CEF) table?
A. CAM
B. TCAM
C. FIB
D. RIB
Questions and Answers
1. Which mechanism is the slowest method for switching packets, where every packet is
inspected by the switch CPU?
A. Cisco Express Forwarding
B. Fast Switching
C. Process Switching
D. Slow Switching
Answer: C
Explanation: Process Switching is the original method for Cisco IOS switching, where every
packet is inspected by the switch CPU. When a packet arrives on the switch, the processor
function is interrupted in order to analyze the packet and compare it to the internal routing
table for forwarding. The next-hop destination attached to the packet is used to determine the
outbound switch interface that should be used for packet delivery. A new Layer 2 frame header
is constructed for every single packet, making this a slow method that is not ideal for modern
networks.
Video Reference: 1.6.1 Process Switching
2. Which switching mechanism is the default method in most modern Cisco IOS devices?
A. Fast Switching
B. Cisco Express Forwarding
C. Process Switching
D. Slow Switching
Answer: B
Explanation: Cisco Express Forwarding (CEF) is the preferred method for modern IOS switching
and is the default method on most modern Cisco devices. CEF stores information in a route
cache for optimized lookup and efficient packet handling. This is much less processor-intensive
than older mechanisms, reserving CPU power for critical operations such as encryption and
QoS.
Video Reference: 1.6.2 Cisco Express Forwarding (CEF)
3. Which memory architecture is used on all Catalyst switch models to perform Layer 2
switching?
A. CAM
B. TCAM
C. FIB
D. RIB
Answer: A
Explanation: The Content Addressable Memory (CAM) table is the memory architecture used in
Cisco Catalyst switches for Layer 2 switching. As data frames arrive on a switchport, the source
MAC addresses for the traffic are recorded in the CAM table. This is used to determine which
outgoing switchport should be used for frame delivery.
Video Reference: 1.6.3 The CAM vs. the TCAM
4. Which switch structure stores IP routing-related information, and is also referred to as the
Cisco Express Forwarding (CEF) table?
A. CAM
B. TCAM
C. FIB
D. RIB
Answer: D
Explanation: The Routing Information Base (RIB) is the location where all information related to
IP routing is stored. This is not specific to any particular routing protocol, but is used by all
protocols such as OSPF, BPG, and so on. Learned routes are inserted into the RIB, including
dynamic, static, and directly connected routes. If a route becomes unreachable it will eventually
be removed from the RIB, based on the timers in use with the protocol related to the route.
Video Reference: 1.6.4 The FIB vs. the RIB
