IT Funkaar

Asalam o alikum , Brothers & sisters. In this tutorial we will learn, How to configure etherchannel on cisco switches.

EtherChannel is a port link aggregation technology or port-channel architecture used primarily on Cisco switches. It allows grouping of several physical Ethernet links to create one logical Ethernet link for the purpose of providing fault-tolerance and high-speed links between switches, routers and servers. A maximum of 8 links can be aggregated to form a single logical link.

There are certain rules / criteria you should keep in mind before configuring Ether-channel.

Criteria – 

1. All ports should be of the same type & should have same speed. (all ports bundled should be Fast Ethernet or Gigabit, Fast ethernet & Gig can’t be combined)
2. Same VLAN configuration (i.e., native VLAN and allowed VLAN should be same)
3. Switch port modes should be same (access or trunk mode)

Further, Ether channel can be configured using protocols such as LACP/PAGP or we can force the link to establish ether channel without any protocol negotiation.. “In this case, mode should be set to ‘on’ at both sides on switches” In this video we will force both sides to establish ether channel without any protocol..

Let’s look into the configuration:

In our topology, we have 2 switches connected with each other. Switch 2 & sw 3 on ports Fa0/1 & Fa0/2. You can see that port Fa0/2 goes to blocking mode due to STP, to avoid loop. After configuring Ether-channel both ports will move to UP state.

First login to SW 2:

(config)# int range fa0/1- 2

(config-if-range)# switchport mode trunk

(config-if-range)# channel-group 1 mode on

Do same configuration on Switch 3. Ether channel should be established now

To verify ether channel , use command:

# sh etherchannel summary

Don’t forget to watch the video tutorial