Cisco CCNA mock exam questions sample test – Question 289

.Which type of switching process requires a switch to wait for the entire frame to be received before forwarding it to a destination port?

A. store and forward
B. cut-through
C. fragment free
D. frame-forward


Correct Answer: A

Explanation:
The store and forward switching process requires a switch to wait until the entire frame is received before forwarding it to a destination port. The store and forward method increases
latency as it buffers the entire frame and runs a Frame Check Sequence (FCS) before forwarding it to destination port. However, it ensures error-free frame forwarding because its
filters all frame errors.
The cut-through switching process does NOT require a switch to verify the FCS in a frame before forwarding it to the destination port. This type of internal switching method is faster
than the store and forward process, but may forward error frames.
The fragment-free switching process only waits to receive the first 64 bytes of the frame before forwarding it the destination port. Fragment-free internal switching assumes that if there
is no error in the first 64 bytes of the data, the frame is error free. The assumption is based on the fact that if a frame suffers a collision, it occurs within the first 64 bytes of data.
Fragment-free forwarding speed lies between that of store and forward and cut-through.
The term frame-forward is not a valid internal switching process for Cisco switches.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Describe and verify switching concepts
References:
Cisco Documentation > Internetworking Case Studies > LAN Switching