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

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 InterSwitch 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

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