CCNA3 (Chapter4)
A network administrator configured an EtherChannel link with three interfaces between two switches. What is the result if one of the three interfaces is down?
The remaining two interfaces continue to load balance traffic. Refer to curriculum topic: 4.1.1 EtherChannel creates an aggregation that is seen as one logical link. It provides redundancy because the overall link is one logical connection. The loss of one physical link within the channel does not create a change in the topology; the EtherChannel remains functional.
When EtherChannel is configured, which mode will force an interface into a port channel without exchanging aggregation protocol packets?
on Refer to curriculum topic: 4.1.2 For both LACP and PAgP, the "on" mode will force an interface into an EtherChannel without exchanging protocol packets.
What are two advantages of EtherChannel? (Choose two.)
1. Configuring the EtherChannel interface provides consistency in the configuration of the physical links. 2. Spanning Tree Protocol views the physical links in an EtherChannel as one logical connection. Refer to curriculum topic: 4.1.1 EtherChannel configuration of one logical interface ensures configuration consistency across the physical links in the EtherChannel. The EtherChannel provides increased bandwidth using existing switch ports without requiring any upgrades to the physical interfaces. Load balancing methods are implemented between links that are part of the same Etherchannel. Because EtherChannel views the bundled physical links as one logical connection, spanning tree recalculation is not required if one of the bundled physical links fail. If a physical interface fails, STP cannot transition the failed interface into a forwarding state.
Which two channel group modes would place an interface in a negotiating state using PAgP? (Choose two.)
1. desirable 2. auto Refer to curriculum topic: 4.1.2 There are three modes available when configuring an interface for PAgP: on, desirable, and auto. Only desirable and auto place the interface in a negotiating state. The active and passive states are used to configure LACP and not PAgP.
What are two load-balancing methods in the EtherChannel technology? (Choose two.)
1. source IP to destination IP 2. source MAC to destination MAC Refer to curriculum topic: 4.1.1 Depending on the hardware platform, one or more load-balancing methods can be implemented. These methods include source MAC to destination MAC load balancing or source IP to destination IP load balancing, across the physical links.
Which two parameters must match on the ports of two switches to create a PAgP EtherChannel between the switches? (Choose two.)
1. speed 2. VLAN Information Refer to curriculum topic: 4.1.2 For an EtherChannel to be created, the ports that are concerned on the two switches must match in terms of the speed, duplex, and VLAN information. The PAgP mode must be compatible but not necessarily equal. The port ID and the MAC addresses do not have to match.
Refer to the exhibit. Which switching technology would allow data to be transmitted over each access layer switch link and prevent the port from being blocked by spanning tree due to the redundant link?
EtherChannel Refer to curriculum topic: 4.1.1 PortFast is used to reduce the amount of time that a port spends going through the spanning-tree algorithm, so that devices can start sending data sooner. Trunking can be implemented in conjunction with EtherChannel, but trunking alone does not aggregate switch links. HSRP is used to load-balance traffic across two different connections to Layer 3 devices for default gateway redundancy. HSRP does not aggregate links at either Layer 2 or Layer 3 as EtherChannel does.
A network administrator is analyzing the features that are supported by different first-hop router redundancy protocols. Which statement is a feature that is associated with GLBP?
GLBP allows load balancing between routers. Refer to curriculum topic: 4.3.1 The GLBP first-hop router redundancy protocol is Cisco proprietary and supports load balancing between a group of redundant routers. VRRPv2 and VRRPv3 are nonproprietary protocols and use a virtual router master.
Which command will start the process to bundle two physical interfaces to create an EtherChannel group via LACP?
GigabitEthernet 0/4 - 5 command Refer to curriculum topic: 4.1.1 To specify the interfaces in an EtherChannel group, use the interface range interface global configuration command for the range of interfaces used. The interface range GigabitEthernet 0/4 - 5 command is the correct option because it specifies two interfaces for the EtherChannel group.
A network administrator is analyzing the features that are supported by different first-hop router redundancy protocols. Which statement describes a feature that is associated with HSRP?
HSRP uses active and standby routers. Refer to curriculum topic: 4.3.1 The HSRP first-hop router redundancy protocol is Cisco proprietary and supports standby and active devices. VRRPv2 and VRRPv3 are nonproprietary. GLBP is Cisco proprietary and supports load balancing between a group of redundant routers.
A network administrator is analyzing first-hop router redundancy protocols. What is a characteristic of VRRPv3?
It supports IPv6 and IPv4 addressing. Refer to curriculum topic: 4.3.1 VRRPv3 is a non-proprietary, first-hop router redundancy protocol. It provides features for both IPv4 and IPv6 addressing. HSRP and GLBP are both Cisco-proprietary protocols. GLBP provides load balancing between a group of redundant routers.
Refer to the exhibit. A network administrator is reviewing the configuration of switch S1. Which protocol has been implemented to group multiple physical ports into one logical link?
PAgP Refer to curriculum topic: 4.1.2 The EtherChannel protocol PAgP provides the grouping of physical interfaces and utilizes the modes of auto and desirable. The EtherChannel protocol LACP provides the grouping of physical interfaces and utilizes the modes of passive and active. DTP and STP are not utilized to group multiple physical interfaces into a single logical link.
Which mode configuration setting would allow formation of an EtherChannel link between switches SW1 and SW2 without sending negotiation traffic?
SW1: on SW2: on Refer to curriculum topic: 4.1.2 The auto channel-group keyword enables PAgP only if a PAgP device is detected on the opposite side of the link. If the auto keyword is used, the only way to form an EtherChannel link is if the opposite connected device is configured with the desirable keyword. PortFast and trunking technologies are irrelevant to forming an EtherChannel link. Even though an EtherChannel can be formed if both sides are configured in desirable mode, PAgP is active and PAgP messages are being sent constantly across the link, decreasing the amount of bandwidth available for user traffic.
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 Refer to curriculum topic: 4.1.1 EtherChannel is utilized on a network to increase speed capabilities by grouping multiple physical ports into one or more logical EtherChannel links between two switches. STP is used to provide redundant links that dynamically block or forward traffic between switches. FHRPs are used to group physical devices to provide traffic flow in the event of failure.
When a range of ports is being configured for EtherChannel, which mode will configure LACP on a port only if the port receives LACP packets from another device?
passive Refer to curriculum topic: 4.1.2 The command channel-group mode active enables LACP unconditionally, and the command channel-group mode passive enables LACP only if the port receives an LACP packet from another device. The command channel-group mode desirable enables PAgP unconditionally, and the command channel-group mode auto enables PAgP only if the port receives a PAgP packet from another device.
When EtherChannel is implemented, multiple physical interfaces are bundled into which type of logical connection?
port channel Refer to curriculum topic: 4.1.1 When EtherChannel is being configured, the first step is to specify what physical ports will be used in an EtherChannel group. The second step is to create the logical EtherChannel port channel interface which contains the group of physical interfaces.
