How to Configure EtherChannel Link Aggregation Control Protocol (LACP) in Cisco Switch
EtherChannel is a port link aggregation technology developed by Cisco, which provides fault-tolerant high-speed links between Switches, Routers, and Servers.
EtherChannel technology allows multiple physical Ethernet links (Fast EtherNet or Gigabit Ethernet) to combine into one logical channel.
There are two protocols used for negotiating EtherChannel and Link Aggregation. We can configure EtherChannel in three ways in Cisco Switches.
- Port Aggregation Protocol (PAgP) - Cisco Proprietary protocol
- IEEE Link Aggregation Control Protocol (LACP) - Industry Standard
- Manual Etherchannel Configuration - Without using any negotiation protocol listed above
Link Aggregation Control Protocol (LACP) is an industry standard defined in IEEE 802.3AD. Using Link Aggregation Control Protocol (LACP), Cisco switches can negotiate Link Aggregation with switches from different vendors that support 802.3AD protocol.
Follow these steps to configure EtherChannel using Link Aggregation Control Protocol (LACP) in Cisco Switches. The ports which are going to be in EtherChannel must be in the shutdown state while configuring the EtherChannel to prevent loops and other related problems.
Switch omnisecu.com.SW1
omnisecu.com.SW1> omnisecu.com.SW1>enable omnisecu.com.SW1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. omnisecu.com.SW1(config)#interface range gigabitEthernet 0/1 - 2 omnisecu.com.SW1(config-if-range)#channel-group 1 mode active omnisecu.com.SW1(config-if-range)#channel-protocol lacp omnisecu.com.SW1(config-if-range)#exit omnisecu.com.SW1(config)#exit omnisecu.com.SW1#
Switch omnisecu.com.SW2
omnisecu.com.SW2>enable omnisecu.com.SW2#configure terminal Enter configuration commands, one per line. End with CNTL/Z. omnisecu.com.SW2(config)#interface range gigabitEthernet 0/1 - 2 omnisecu.com.SW2(config-if-range)#channel-group 1 mode active omnisecu.com.SW2(config-if-range)#channel-protocol lacp omnisecu.com.SW2(config-if-range)#exit omnisecu.com.SW2(config)#exit omnisecu.com.SW2#
omnisecu.com.SW1#show ip interface brief Interface IP-Address OK? Method Status Protocol <output_omitted> GigabitEthernet0/1 unassigned YES unset up up GigabitEthernet0/2 unassigned YES unset up up Vlan1 unassigned YES unset administratively down down Port-channel 1 unassigned YES unset up up <output_omitted>