Switching Method
tuscani
Member Posts: 121
in CCNA & CCENT
One type of frame switching uses low-latency forwarding and then switches to a
higher-latency error checking mode when an error threshold is exceeded. What is
the name of this frame switching mode?
A. store and forward
B. fragment-free
C. adaptive cut-through
D. fast-forward
Answer: C
Explanation: Adaptive cut-through is a modified form of cut-through switching in
which the switch waits for the collision window (64 bytes) to pass before forwarding.
It means that each frame will be checked into the data field to make sure no
fragmentation has occurred.
I picked... B.. Is it really C?
higher-latency error checking mode when an error threshold is exceeded. What is
the name of this frame switching mode?
A. store and forward
B. fragment-free
C. adaptive cut-through
D. fast-forward
Answer: C
Explanation: Adaptive cut-through is a modified form of cut-through switching in
which the switch waits for the collision window (64 bytes) to pass before forwarding.
It means that each frame will be checked into the data field to make sure no
fragmentation has occurred.
I picked... B.. Is it really C?
Comments
The key, or the way that they make it clear, is when the question says that the method "switches" and begins scanning a larger portion of the frames. If it receives too many errors, it begins adapting.
2x 2950
2x 3550
2x 2650XM
2x 3640
1x 2801
cut-through doesn't care about anything...
I re-checked my book... since as you... I didn't like the adaptive stuff. According to my info, 3 types of switching:
Cut-through (or FastForward according to Cisco).
FragmentFree (Modified Cut-Through)
Store-and-forward.
So, your answer should be... D
Dont make the assumption that everything you need for the exam is in your book! Multiple sources are a must.