Day 9 EtherChannel Lab | PAgP Configuration | Port Aggregation Protocol | LACP Configuration

EtherChannel Configuration, EtherChannel Troubleshooting, port link aggregation technology, port-channel architecture, PAgP-Port Aggregation Protocol, LACP (Link Aggregation Control Protocol).

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.
The switch and STP will treat the bundled ports as a single interface, eliminating the possibility of a switching loop.
There are two issues with using only a single physical port for the trunk connection:
• The port represents a single point of failure. If the port goes down, the trunk connection is lost.
• The port represents a traffic bottleneck. All other ports on the switch will use that one port to communicate across the trunk connection.
benefits of adding redundancy to the trunk connection are fault tolerance and increased bandwidth, via load balancing.

There are two methods of configuring an EtherChannel:
• Manually • Dynamically

To manually configure two ports to join an EtherChannel:
Switch(config)# interface range gi2/23 - 24
Switch(config-if)# channel-group 1 mode on
Switch(config)#int port-channel 4
Switch(config-if)#switchport trunk encapsulation Dot1q
Switch(config-if)# switchport mode trunk
Switch# show int trunk
Switch# show spanning-tree