Cisco CCNA mock exam questions sample test – Question 435

.You have executed the following commands on a switch:
Switch64(config)# interface range gigabitethernet2/0/1 -2
Switch64(config-if-range)# switchport mode access
Switch64(config-if-range)# switchport access vlan 10
Switch64(config-if-range)# channel-group 5 mode auto
In which of the following situations will Switch64 create an Etherchannel?

A. If the other switch is set for desirable mode
B. If the other switch is set for auto mode
C. If the other switch is set for on mode
D. If the other switch is set for passive mode

Correct Answer: A

Explanation:
The Etherchannel will be created if the other end is set to desirable mode. The configuration shown in the example is using Port Aggregation protocol (PAGP). This protocol has two
settings: desirable and auto. Two ends will negotiate and will only create an Etherchannel under two conditions: if one end is set to auto and the other end is set to desirable, or if both
ends are set for desirable.
It will not form an Etherchannel if the other end is set to auto mode. When both ends are set to auto mode, an Etherchannel will not form.
It will not form an Etherchannel if the other end is set to on mode. On mode disables negotiation of any kind, which will prevent an Etherchannel from forming unless the other end is
also set for on.
It will not form an Etherchannel if the other end is set to passive mode. Passive is a setting used in Link Aggregation Protocol (LACP). The two protocols are not compatible.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot (Layer 2/Layer 3) EtherChannel
References:
Catalyst 3750-X and 3560-X Switch Software Configuration Guide, Release 12.2(55)SE > Chapter: Configuring EtherChannels