CCNA 3 discovery - module 3 chapter 3 Exam answers

1. A router has two serial interfaces and two Fast Ethernet interfaces. This router must be connected to a WAN link and to a switch that supports four VLANs. How can this be accomplished in the most efficient and cost-effective manner to support inter-VLAN routing between the four
VLANs?

a. Connect a smaller router to the serial interface to handle the inter-VLAN traffic.
b. Add two additional Fast Ethernet interfaces to the router to allow one VLAN per interface.
c. Connect a trunked uplink from the switch to one Fast Ethernet interface on the router and create logical subinterfaces for each VLAN. ****
d. Use serial-to-Fast Ethernet transceivers to connect two of the VLANs to the serial ports on the router. Support the other two VLANs directly to the available FastEthernet ports.

2. Which three steps should be taken before moving a Catalyst switch to a new VTP management domain? (Choose three.)

a. Reboot the switch.
b. Reset the VTP counters to allow the switch to synchronize with the other switches in the domain. ******
c. Download the VTP database from the VTP server in the new domain.
d. Configure the VTP server in the domain to recognize the BID of the new switch. ******
e. Select the correct VTP mode and version.
f. Configure the switch with the name of the new management
domain. *****

3. Which two items will prevent broadcasts from being sent throughout the network? (Choose two.)

a- bridges
b- routers ****
c- switches
d- VLANs ****
e- hubs

4 Which two criteria are used by STP to select a root bridge?(Choose two.)

a- memory size
b- bridge priority ****
c- switching speed
d- number of ports
e- base MAC address ****
f- switch
g- location

5- When are MAC addresses removed from the CAM table?

a- at regular 30 second intervals
b- when a broadcast packet is received
c- when the IP Address of a host is changed
d- after they have been idle for a certain period of time ****

6- What is the purpose of VTP?

a- maintaining consistency in VLAN configuration across the network ****
b- routing frames from one VLAN to another
c- routing the frames along the best path between switches
d- tagging user data frames with VLAN membership information
e- distributing BPDUs to maintain loop-free switched paths

7- Which statement best describes adaptive cut-through switching?

a. The switch initially forwards all traffic using cut-through switching and then changes to store-and-forward switching if errors exceed a threshold value.
b. The switch initially forwards all traffic using cut-through switching and then changes to fast forward switching if errors exceed a threshold value. *****
c. The switch initially forwards all traffic using cut-through switching and then temporarily disables the port if errors exceed a threshold value.
d. The switch initially forwards all traffic using store-and-forward switching and then changes to cut-through switching if errors exceed a threshold value.

8- Which three must be used when a router interface is configured for VLAN trunking? (Choose three.)

a. one subinterface per VLAN ****
b. one physical interface for each subinterface
c. one IP network or subnetwork for each subinterface ****
d. one trunked link per VLAN
e. a management domain for each subinterface
f. a compatible trunking protocol encapsulation for each subinterface ****



9- In which STP state does a switch port transmit user data and learn MAC addresses?

a. blocking
b. learning
c. disabling
d. listening
e. forwarding ***


10 - Using STP, how long does it take for a switch port to go from the blocking state to the forwarding state?

a. 2 seconds
b. 15 seconds
c. 20 seconds
d. 50 seconds ****

11 -The information contained in a BPDU is used for which two purposes?
(Choose two.)

a. to prevent loops by sharing bridging tables between connected switches ****
b. to set the duplex mode of a redundant link
c. to determine the shortest path to the root bridge ****
d. to determine which ports will forward frames as part of the spanning tree
e. to activate looped paths throughout the network

12- Which Catalyst feature causes a switch port to enter the spanning-tree forwarding state immediately?

a. backbonefast
b. uplinkfast
c. portfast *****
d. rapid spanning tree

13 - Which two characteristics describe a port in the STP blocking state?
(Choose two.)

a. provides port security ****
b. displays a steady green light
c. learns MAC addresses as BPDUs are processed
d. discards data frames received from the attached segment ****
e. receives BPDUs and directs them to the system module


14 What is the first step in the process of convergence in a spanning tree topology?

a. election of the root bridge ****
b. determination of the designated port for each segment
c. blocking of the non-designated ports
d. selection of the designated trunk port
e. activation of the root port for each segment