CCNA 3 Exam 3
Which spanning tree standard supports only one root bridge so that traffic from all VLANs flows over the same path?
802.1D
Which two protocols are link aggregation protocols?
802.3ad PAgP
Which statement describes an EtherChannel implementation?
A trunked port can be part of an EtherChannel bundle.
Which Cisco switch feature ensures that configured switch edge ports do not cause Layer 2 loops if a port is mistakenly connected to another switch?
BPDU guard
What is a characteristic of a Layer 2 loop?
Broadcast frames are forwarded back to the sending switch.
PVST+
Cisco implementation of IEE 802.1D
The trunk link between two 2960 switches has reached its capacity. How can this be addressed in the most economical way?
Combine physical ports into a high-speed logical link by configuring EtherChannel.
Which switching technology would allow each access layer switch link to be aggregated to provide more bandwidth between each Layer 2 switch and the Layer 3 switch?
EtherChannel
RSTP
Fast converging enhancement of IEEE 802.1D
In which two PVST+ port states are MAC addresses learned? (Choose two.)
Forwarding and Learning
MSTP
IEEE standard that reduces the number of STP instances
Which statement is true regarding the use of PAgP to create EtherChannels?
It is Cisco proprietary.
Which statement describes a characteristic of EtherChannel?
It is made by combining multiple physical links that are seen as one link between two switches.
A network administrator is preparing the implementation of Rapid PVST+ on a production network. How are the Rapid PVST+ link types determined on the switch interfaces?
Link types are determined automatically.
Which three components are combined to form a bridge ID?
MAC address extended system ID bridge priority
Which protocol provides up to 16 instances of RSTP, combines many VLANs with the same physical and logical topology into a common RSTP instance, and provides support for PortFast, BPDU guard, BPDU filter, root guard, and loop guard?
MST
What is the outcome of a Layer 2 broadcast storm?
New traffic is discarded by the switch because it is unable to be processed.
Which three settings must match in order for switch ports to form an EtherChannel?
Non-trunk ports must belong to the same VLAN. The interfaces must be configured to the same speed. The duplex settings of the switch ports on both sides of the physical link must match.
What is an advantage of PVST+?
PVST+ optimizes performance on the network through load sharing.
What is the purpose of the Spanning Tree Protocol (STP)?
Prevents Layer 2 loops
Rapid PVST+
Proprietary per VLAN implementation of IEEE 802.1w
Which two network design features require Spanning Tree Protocol (STP) to ensure correct network operation? (Choose two.)
Redundant links between Layer 2 switches, Removing single points of failure with multiple Layer 2 switches
An EtherChannel link using LACP was formed between two switches, S1 and S2. While verifying the configuration, which mode combination could be utilized on both switches?
S1-passive and S2-active
Which two types of spanning tree protocols can cause suboptimal traffic flows because they assume only one spanning-tree instance for the entire bridged network? (Choose two.)
STP and RSTP
A network administrator is configuring an EtherChannel link between switches SW1 and SW2 by using the command SW1(config-if-range)# channel-group 1 mode passive. Which command must be used on SW2 to enable this EtherChannel?
SW2(config-if-range)# channel-group 1 mode active
Refer to the exhibit. Which switch will be elected the root bridge and which switch will place a port in blocking mode? (Choose two.)
SW3 will become the root bridge because lowest MAC address. SW4 will get a port blocked.
What is a best practice to use before beginning an EtherChannel implementation?
Shut down each of the affected interfaces.
What port type is used to interconnect switches in a switch stack?
StackWise
Open the PT Activity. Perform the tasks in the activity instructions and then answer the question. Which switch is the root bridge?
Switch_4
Refer to the exhibit. A network administrator issued the show etherchannel summary command on the switch S1. What conclusion can be drawn?
The EtherChannel is not functional.
To obtain an overview of the spanning tree status of a switched network, a network engineer issues the show spanning-tree command on a switch. Which two items of information will this command display? (Choose two.)
The role of the ports in all VLANs. The root bridge BID.
The administrator tried to create an EtherChannel between S1 and the other two switches via the commands that are shown, but was unsuccessful. What is the problem?
Traffic cannot be sent to two different switches through the same EtherChannel link.
Refer to the exhibit. Which trunk link will not forward any traffic after the root bridge election process is complete?
Trunk 2
What additional information is contained in the 12-bit extended system ID of a BPDU?
VLAN ID
Which three options must match in order to establish an EtherChannel between two directly connected switches?
VLAN memberships of the interfaces that are used for EtherChannel speed of the interfaces that are used for EtherChannel duplex settings of the interfaces that are used for EtherChannel
When a range of ports is being configured for EtherChannel, which mode will configure LACP so that it initiates the EtherChannel negotiation?
active
What is the most cost-effective method of solving interface congestion that is caused by a high level of traffic between two switches?
aggregate ports by using EtherChannel
What is an advantage of using LACP?
allows automatic formation of EtherChannel links
What are two advantages of using LACP?
allows automatic formation of EtherChannel links allows use of multivendor devices
When a range of ports is being configured for EtherChannel by the use of PAgP, which mode will form the bundled channel only if the port receives PAgP packets from another device?
auto
Which RSTP ports are connected to end devices?
edge ports
Which port state will switch ports immediately transition to when configured for PortFast?
forwarding
Which two port states does a switch learn MAC addresses and process BPDUs in a PVST network? (Choose two.)
forwarding and learning
As the network administrator you have been asked to implement EtherChannel on the corporate network. What does this configuration consist of?
grouping multiple physical ports to increase bandwidth between two switches
Which command will initiate EtherChannel interface configuration mode?
interface port-channel interface-identifier
If no bridge priority is configured in PVST, which criteria is considered when electing the root bridge?
lowest MAC address
The spanning-tree _______ global configuration command is used to enable Rapid PVST+.
mode rapid-pvst
This command shows the list of ports involved in the port channel and the time since the ports were bundled.
show etherchannel port-channel
This command is used to check what port channels are configured on a switch.
show etherchannel summary
This command shows information about the status of the port involved in the Etherchannel.This command shows information about the status of the port involved in the Etherchannel.
show interfaces fa0/2 etherchannel
This command shows information about the reliability of the port-channel.
show interfaces port-channel1
Which two load balancing methods can be implemented with EtherChannel technology?
source MAC to destination MAC source IP to destination IP
Which STP priority configuration would ensure that a switch would always be the root switch?
spanning-tree vlan 10 priority 0
Which PAgP mode combination will establish an EtherChannel?
switch 1 set to desirable; switch 2 set to desirable.
