EtherChannel is a way to provide redundant links and not be affected by Spanning Tree Protocol (STP). By design, when you connect multiple links to switches, STP will shut down the excess links to prevent loops. There is a Cisco version and an IEEE version. Cisco’s is called Port Aggregation Protocol (PAgP), and the IEEE 802.3ad standard is called Link Aggregation Control Protocol (LACP). PAgP and LACP are negotiation protocols. EtherChannel can also manually be configured.
Cisco EtherChannel allows us to bundle up to eight active ports between switches. The keywords change according to the technology you are looking to configure. Both sides of the EtherChannel must use the same technology.
Link Aggregation Protocol (LACP) configuration uses active / passive.
Port Aggregation Protocol (PaGP) configuration uses auto / desirable.
Manual configuration uses on.
Configuration
The following configuration is for Layer 2 EtherChannel.
Switch#configure terminal
Switch(config)#interface range interface-id - interface-id
Switch(config-of-range)#switchport trunk encapsulation dot1q
Switch(config-of-range)#switchport mode trunk
Switch(config-of-range)#channel-group group-id mode {active | auto | desirable | on | passive}
Switch(config-of-range)#exit
Verify
Switch#show etherchannel port-channel
Switch#show etherchannel summary
Leave a Reply