EtherChannel - jibingl/CCNA-CCNP GitHub Wiki

Aka Port Channel or Link Aggregation Croup (LAG)

Class	Full-name	Property	Up to Interfaces
PAgP	Port Aggregation Protocol	Cisco	8
LACP	Link Aggregation Control Protocol	Public	8/16
Static	Static EtherChannel		8

Syntax

SW1(config)#interface [range] {interface | interface-range}
SW1(config-if-range)#channel-group <number> mode <eth-channel-mode>     //channel-group number locally significant in the switch.
                                    1-255         auto|desirable        //For PAgP.
                                                  active|passive        //For LACP.
                                                  on                    //Static.

EtherChannel Forming Table

Modes	auto/passive	desirable/active	on
auto/passive	X	Eth-channel	X
desirable/active	Eth-channel	Eth-channel	X
on	X	X	Eth-channel

Configuration Requiements

All member-interfaces must have matching configurations:

Same duplex (full/half);
Same speed;
Same switchport mode (access/trunk)
Same allowed VLANs/native VLAN (for trunk interfaces)

If not matching, the mis-config interface will be excluded while EtherChannel still works with other member-interfaces matching the requirements.

Load Banlance Methods

Methods used to calculate in EtherChannel load balancing can be configured as one of dst-ip, dst-mac, src-dst-ip, src-dst-mac, src-ip, src-mac. Example:

SW1#show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
      src-dst-ip
EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address
  IPv6: Source XOR Destination IP address

SW1#conf t
SW1(config)#port-channel load-balance sc-dst-mac
SW1(config)#do show etherchannel load-blalance
EtherChannel Load-Balancing Configuration:
      src-dst-mac
EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination MAC address
  IPv6: Source XOR Destination MAC address