Learn Network LACP Concepts and Settings

 

This time, we will learn about the principles of LACP operation and how to set it up in the network.

 

1. LACP (Link aggregation Contorol Protocol)

 

 

※ LACP

: Technology that binds multiple physical ports to act as a single logical port.

 

 

Full name of LACP : IEEE 802.3ad (standard protocol)

The same proprietary protocol created by Multi-port Trunking or Cisco is EtherChannel.

 

 

 

 

2. How to set up LACP

 

 

1) Static settings (used when connecting between the same vendors)

 

2) Dynamic settings (used to connect equipment between different equipment) - Active mode - Passive mode: Mode may vary slightly from vendor to vendor (based on Alcatel switch)

 

 

 

★ LACP Advantage

 

- LACP can overcome the limitation of the capacity of individual links.

(When one port is 100 Mbps, you can bundle four and increase it to 400 Mbps of bandwidth.)

 

- It is possible to avoid disconnection of the link in the event of a failure.

(Even if one line fails, the remaining ports allow uninterrupted normal service continuity)

 

 

- Load-balancing is possible for logically connected ports.

 

- Cost reduction

(When 6G bandwidth is required, equipment must be replaced unless it is a switch that typically supports 6G or higher, but this LACP feature allows you to use it without replacing equipment, eliminating unnecessary investment.)

 

 

 

※ How to load balance

 

Apply the Hash function to the Ethernet Frame MAC address value to determine the physical port to be used in the output.

 

You can apply the hash function to a source MAC or destination MAC address. (Or switches that apply fields from IP header (IP address), TCP/UDP header (Port #) to hash functions in addition to MAC addresses)

 

 

 

3. Common sense of LACP that you must be familiar with.

 

 

- LACP can only be set to even numbers, not odd numbers

 

: For example, even if you want to tie up three 1G ports, you have to tie up four 1G ports and connect only three cables. As a policy, ports should be set to even number of ports.

 

 

Normally, you can set the same vendor in a normal setting, and when connecting with other vendors, you should proceed with the LACP mode well.

 

EX) Cisco Switch <==> Alcatel Switch

 

In this way, when vendors connect two different switches with LACP, they usually use Dynamic mode to set them up.

 

I'll be careful. When you connect with other vendors, make sure to check if there's anything wrong after you finish setting up.

 

In particular, Cisco switches use their own protocol, so when connecting with other vendors, check the status/fail-over and finish the work.

 

 

저의 글을 읽어 주셔서 감사합니다. 오늘도 즐거운 하루 보내세요.