Cisco 2 - Module 6

Which two protocols are link aggregation protocols? (Choose two.)

- PAgP - 802.3ad Explanation: (The two protocols that can be used to form an EtherChannel are PAgP (Cisco proprietary) and LACP, also know as IEEE 802.3ad. STP (Spanning Tree Protocol) or RSTP (Rapid Spanning Tree Protocol) is used to avoid loops in a Layer 2 network. EtherChannel is the term that describes the bundling of two or more links that are treated as a single link for spanning tree and configuration.)

A network administrator is configuring an EtherChannel link between two physical ports on a switch. Which statement describes the result when one of the physical ports fails?

The EtherChannel continues transmitting data with reduced bandwidth. Explanation: (An EtherChannel is seen as one logical connection. The loss of one physical link within the channel does not create a change in the topology and therefore a spanning tree recalculation is not required. When one of the member ports in the EtherChannel fails, the EtherChannel link remains functional, although its overall throughput decreases because of a lost link within the EtherChannel.)

What will happen if a network administrator puts a port that is part of an EtherChannel bundle into a different VLAN than the other ports in that bundle?

The EtherChannel will fail. Explanation: (All ports in an EtherChannel bundle must either be trunk ports or be access ports in the same VLAN. If VLAN pruning is enabled on the trunk, the allowed VLANs must be the same on both sides of the EtherChannel.)

Which are benefits of EtherChannel technology? (Choose all that apply.)

- Fault-Tolerance - Load Sharing - Increased Bandwidth - Link Redundancy

True or False? FastEthernet and GigabitEthernet links can be combined into a single EtherChannel.

False

When EtherChannel is implemented, multiple physical interfaces are bundled into which type of logical connection?

Port Channel Explanation: (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.)

Which two mode combinations would result in the successful negotiation of an EtherChannel? (Choose two.

- active; passive - desirable; desirable Explanation: (The combinations of modes that will form an EtherChannel are as follows: on/on, active/passive, active/active, desirable/auto, and desirable/desirable.)

Which combinations of PAgP modes will form an EtherChannel? (Choose all that apply.)

- auto > desirable - on > on

Which three interface parameters must match for an EtherChannel to form? (Choose three.)

- native VLAN - trunking mode - allowed VLANs Explanation: (There are some EtherChannel modes that can be different and an EtherChannel will form, such as auto/desirable and active/passive. A port that is currently in the spanning tree blocking mode or has been configured for PortFast can still be used to form an EtherChannel.)

Which three are PAgP interface modes? (Choose three.)

- on - auto - desirable

Which function is provided by EtherChannel?

Creating one Logical Link by using Multiple Physical Links between two LAN Switches. Explanation: (EtherChannel technology allows the grouping, or aggregating, of several Fast Ethernet or Gigabit switch ports into one logical channel.)

True or False? PAgP and LACP are both Cisco-proprietary link aggregation protocols.

False

When a range of ports is being configured for EtherChannel, which mode will configure LACP so that it initiates the EtherChannel negotiation?

active Explanation: (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.)

Which two load balancing methods can be implemented with EtherChannel technology? (Choose two.)

- Source IP to Destination IP - Source MAC to Destination MAC Explanation: (Source MAC to destination MAC load balancing and source IP to destination IP load balancing are two implementation methods used in EtherChannel technology.)

What are three advantages of using EtherChannel technology? (Choose three.)

- There is no need to upgrade links to faster connections to increase bandwidth. - Configuration tasks can be done on the EtherChannel interface. - A spanning tree recalculation is not required when a single link within the channel goes down. Explanation: (Most configuration tasks can be done on the EtherChannel interface, rather than on individual ports. Existing ports can be used, eliminating the need to upgrade ports to faster speeds. Spanning Tree Protocol runs on EtherChannel links in the same manner as it does on regular links, but it does not recalculate when an individual link within the channel goes down. EtherChannel also supports load balancing.)

Which statement is true about EtherChannel technology?

EtherChannel uses existing Switch Ports. Explanation: (EtherChannel relies on existing switch ports, so there is no need to upgrade the links. Some configuration tasks are done on individual ports and some configuration tasks are done on the EtherChannel group. STP operates on EtherChannel in the same manner as it does on other redundant links.)

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 Explanation: (An EtherChannel link will be formed using LACP when both switches are in on mode or in active mode, or when one of them is in passive mode and the other is in active mode.)

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 Explanation: (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.)

Which PAgP interface mode will initiate negotiation with other interfaces?

desirable

When a range of ports is being configured for EtherChannel, which mode will configure PAgP so that it initiates the EtherChannel negotiation?

desirable Explanation: (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 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 Explanation: (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.)