EtherChannel Overview and Configuration guidelines.

EtherChannel Overview:

EtherChannel provides fault-tolerant, high-speed links between the switches, routers, and servers. An Ether-Channel consists of individual Fast-Ethernet or Gigabit-Ethernet links bundled into a single logical link. If a link within an EtherChannel fails, the traffic previously carried over that failed link changes to the remaining links within the Ether-Channel.

Interface Modes in EtherChannel:

Mode: On

Protocol: None

Detail: It forces the interface into an Ether-Channel without Port Aggregation Protocol or Link Aggregation Control Protocol. In which Channel only exists if connected to another interface group also in On mode.

Mode: Auto

Protocol: PAgP (Cisco Proprietary)

Detail: It will respond to PAgP packets but will not initiate PAgP negotiation

Mode: Desirable

Protocol: PAgP (Cisco Proprietary)

Detail: It will send PAgP packets to start negotiations.

Mode: Passive

Protocol: LACP (IEEE Proprietary) Passive Negotiations

Detail: It will respond to LACP packets but will not initiate LACP negotiation.

Mode: Active

Protocol: LACP (IEEE Proprietary) Active Negotiations

Detail: It will send LACP packets to start negotiations.

Guidelines for EtherChannel Configuration:

■  Port Aggregation Protocol is Cisco proprietary and not compatible with the Link Aggregation Control Protocol.

■  LACP is defined in IEEE 802.3ad.

■  A single EtherChannel can be made by combining two to eight parallel links.

■  All ports must be followed below conditions:

■  Speed and duplex must be Same

■  It Cannot mix Fast Ethernet and Gigabit Ethernet

■  It Cannot mix PAgP and LACP

■  It Must all be VLAN trunk or non-trunk operational status

■  All links must be either Layer 2 or Layer 3 in a single channel group member.

■  For the creation of a channel in PAgP, The sides must be set to one of the following:

■  Auto-Desirable

■  Desirable-Desirable

■  For the creation of a channel in LACP, The sides must be set to either:

■  Active-Active

■  Active-Passive

■  For creating a channel without using PAgP or LACP, The sides must be set to On-On.

■  An interface that is already configured to be a Switched Port Analyzer (SPAN) destination port will not part of an EtherChannel group until SPAN is disabled.

■  Don’t configure a secure port as part of an EtherChannel.

■  The Interfaces with different native VLANs cannot form an EtherChannel.

■  When using trunk links, Please ensure that all trunks ports are in the same trunking mode Inter-Switch Link (ISL) or dot1q.

Layer 2 EtherChannel Configuration:

L2Switch(config)#interface port-channel {number} 

L2Switch(config)#interface {Parameter}

     L2Switch(config)#interface range fastethernet 0/1 -6

L2Switch(config-if range)#channel-group 1 mode on

L2Switch(config-if-range)#channel-group 1 mode desirable

     L2Switch(config-if-range)#channel-group 1 mode active

If you are entering the channel-group command in the physical port interface mode without first setting a port-channel command in global configuration mode, the port-channel will automatically be created for us.

L3 EtherChannel Configuration:

L3Switch(config)#interface port-channel 1

L3Switch(config-if)#no switchport

L3Switch (config-if)#ip address 192.168.10.1 255.255.255.0

L3Switch (config-if)#exit

     L3Switch (config)#interface range fastethernet 0/20 – 23

L3Switch (config-if)#no switchport

L3Switch (config-if-range)#no IP address

L3Switch (config-if- range)#channel-group 1 mode on

L3Switch (config-if-range) #channel-group 1 mode desirable

L3Switch (config-if- range)#channel-group 1 mode active

Verifying EtherChannel:

L3Switch#show running-config

L3Switch#show running-config interface fastethernet 0/12

L3Switch#show interfaces fastethernet 0/12 etherchannel

L3Switch#show etherchannel

L3Switch#show etherchannel 1 port-channel

L3Switch#show etherchannel summary

L3Switch#show interface port-channel 1

L3Switch#show pagp neighbor

L3Switch#clear pagp 1 counters

L3Switch#clear lacp 1 counter

                    THANK YOU