Cisco CCNA mock exam questions sample test – Question 71

.Which of the following is a frame tagging method for identifying Virtual LAN (VLAN) memberships over trunk links?

A. STP
B. RIP
C. CDP
D. 802.1q

Correct Answer: D

Explanation:
802.1q is a frame tagging method for identifying Virtual LAN (VLAN) memberships over trunk links. Frame tagging ensures identification of individual VLAN frames over a trunk link
that carries frames for multiple VLANs. This frame tagging method is a standardized protocol developed by The Institute of Electrical and Electronics Engineers (IEEE). Cisco has also
developed a proprietary frame tagging method, known as Inter-Switch Link (ISL).
When configuring a trunk link between a router and a switch, you must configure the physical interface on the router with one subinterface for each VLAN, and you must configure the
physical ports on the router and the switch with the same encapsulation type, whether 802.1q or ISL.
Spanning Tree Protocol (STP) is not a frame tagging method, but a protocol used to remove switching loops in redundantly configured switched environments and create a single
active Layer 2 path between any two network segments. Whenever a network segment can be handled by more than one switch, STP will elect one switch to take responsibility, and
the other switches will be placed into a blocking state for the ports connected to that segment. In this way, only one switch receives and forwards data for this segment, removing the
potential for generating multiple copies of the same frame. The benefits of STP include:
Prevention of broadcast storms
Prevention of multiple frame copies
Media Access Control (MAC) address database stability
Routing Information Protocol (RIP) is not a frame tagging method, but a distance vector routing protocol. It populates routing tables dynamically about the topology changes.
Cisco Discovery Protocol is not a frame tagging method, but a Cisco proprietary protocol used to collect hardware and protocol information for directly connected Cisco devices. CDP
has nothing to do with VLANs.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot VLANs (normal/extended range) spanning multiple switches
References:
Cisco > Support > Technology Support > LAN Switching > Layer-Three-Switching and Forwarding > Configure > Configuration Examples and Technotes > Configuring InterVLAN
Routing and ISL/802.1Q Trunking on a Catalyst 2900XL/3500XL/2950 Switch Using an External Router