Cisco CCNA mock exam questions sample test – Question 380

.Which of the following technologies allows a switch port to immediately transition to a forwarding state?

A. Rapid STP
B. PortFast
C. VTP
D. CDP

Correct Answer: B

Explanation:
PortFast is a technology that allows a switch port connected to an end node such as a workstation, server, or printer to bypass the normal Spanning Tree Protocol (STP) convergence
process. When a new device is powered up on a switch port, it will immediately transition to a forwarding state.
NOTE: PortFast should only be used on access ports. It should not be used on trunk ports or on ports that connect to hubs, routers and other switches.
Rapid STP (RSTP) is a new STP standard that provides faster convergence than the original 802.1d STP. RSTP supports PortFast, but it must be configured explicitly.
The VLAN Trunking Protocol (VTP) does not allow for immediate transition to a forwarding state. VTP is used to synchronize VLAN databases between switches, and has no effect on
STP.
The Cisco Discovery Protocol (CDP) does not allow for immediate transition to a forwarding state. CDP is used to verify connectivity and document directly connected Cisco devices.
CDP is not related to STP.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot STP-related optional features
References:
Cisco > Support > Configuring Spanning Tree PortFast, BPDU Guard, BPDU Filter, UplinkFast, and LoopGuard > Understanding How PortFast Works