ETHERCHANNEL INTERVIEW QUESTIONS & ANSWERS

Q: What is EtherChannel?

Ans: EtherChannel is an aggregation or bundling of multiple physical links into a single virtual link.

Q: Benefits of EtherChannel?

Ans:

• It provides more bandwidth by combining multiple physical links into a single virtual link.

• It offers redundancy.

  
  

Q: What are the parameters to be the same to configure EtherChannel?

Ans:

• Same duplex

• Same speed

• Same VLAN

• Trunk or access mode must be the same.

  
  

Q: How many interfaces can aggregate or bundle using EtherChannel?

Ans: We can aggregate up to 16 interfaces. 8 will be active, and 8 will be standby.

Q: Is EtherChannel Layer 2 or Layer 3?

Ans: EtherChannel is both Layer 2 and Layer 3.

Q: How many types to configure EtherChannel?

Ans:

1. Manual (Static EtherChannel)

2. PAgP (Port Aggregation Control Protocol)

3. LACP (Link Aggregation Control Protocol)

4. 
   

Q: Difference between PAgP and LACP?

Ans:

• PAgP (Port Aggregation Control Protocol): Cisco proprietary.

• LACP (Link Aggregation Control Protocol): Open standard.

  
  

Q: Can we configure EtherChannel between different devices?

Ans: Yes. EtherChannel can be configured between:

• Switch to Server

• Switch to Router

  
  

Q: Modes used in PAgP and LACP to form EtherChannel?

Ans:

• LACP: Active, Passive

• PAgP: Auto, Desirable

  
  

Q: Configuration of EtherChannel?

Ans:

bash

Copy

# int range fa0/1-2 # channel-group 1 mode <on/auto/desirable/active/passive>

Q: How does EtherChannel load balance the traffic?

Ans: EtherChannel uses a load balancing algorithm to send traffic based on one of the following criteria:

• Source IP

• Destination IP

• Source-Destination IP

• Source MAC

• Destination MAC

• Source Port

• Destination Port