During the process of connecting four switches to the central router and implementing VLANS between the
devices, it becomes apparent that there was a misunderstanding about which encapsulation protocol to use on
the links between the switches and the router.
If there is mismatch between the encapsulation types used on the router interface and the type used on the
connected switch port, what will be the result?
A.
The relevant switch ports will be green.
B.
The relevant switch ports will be amber.
C.
The relevant switch ports will be neither green nor amber.
D.
The relevant switch ports will be green and flashing.
Explanation:
If there is a mismatch between the encapsulation types used on the router interface and the type used on the
connected switch port, the link will not be functional and there will be neither an amber nor a green light. The
same outcome will be produced when there is a bad cable, an incorrect cable type, or a lack of signal. An
example of a cable mismatch would be the use of a straight-through cable when the situation required a
crossover cable, or vice versa.
When connecting switch ports to routers, there are two possible encapsulation types: the default Interswitch
Link (ISL) and the 802.1q standard. ISL is a Cisco proprietary technology; therefore, it can only be used
between Cisco products. 802.1q is an industry standard that can be used between Cisco and non-Cisco
products. If the same type is not configured on each end, the link will not work.
The relevant switch ports will not be green. Green indicates normal operation with no activity.
The relevant switch ports will not be amber. Amber indicates the link is administratively down. The amber light
is usually flashing as well.
The relevant switch ports will not be green and flashing. This display indicates normal operation with activity on
the line.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Troubleshoot interface and cable issues (collisions, errors, duplex, speed)