How to Configure EtherChannel (LACP) on Cisco Switches, Windows, and Linux

EtherChannel on two Switches

Setting up

Let's start with a simple configuration where we have two vlans (1 and 2, to keep things simple) and a trunk interface between two switches. To improve the bandwidth between them, we'll create an EtherChannel on the trunk interface, consisting of two Gigabit links.

⚠️ The GigabitEthernet1/0/25 and GigabitEthernet1/0/26 interfaces of both switches must have exactly the same configuration to work (trunk, allowed vlan etc…).⚠️

• Configure switch01:

switch01(config)# interface range GigabitEthernet1/0/25-26
switch01(config-if-range)# switchport mode trunk
switch01(config-if-range)# switchport trunk allowed none
switch01(config-if-range)# switchport trunk allowed vlan 1,2
switch01(config-if-range)# channel-protocol lacp
switch01(config-if-range)# channel-group 1 mode passive

• Configure switch02:

switch02(config)# interface range GigabitEthernet1/0/25-26
switch02(config-if-range)# switchport mode trunk
switch02(config-if-range)# switchport trunk allowed none
switch02(config-if-range)# switchport trunk allowed vlan 1,2
switch02(config-if-range)# channel-protocol lacp
switch02(config-if-range)# channel-group 1 mode active

• We can now configure the EtherChannel interface like any other interface, using the name Po 1:

switch02(config)# interface port-channel 1

Check configuration

• Check EtherChannel status:

switch01# show etherchannel summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      N - not in use, no aggregation
        f - failed to allocate aggregator

        M - not in use, minimum links not met
        m - not in use, port not aggregated due to minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

        A - formed by Auto LAG


Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Gi1/0/25(P)    Gi1/0/26(P)

• Check the load-balancing method currently in use:

switch01# 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

• Check the effectiveness of the configured load-balancing method:

switch01# show etherchannel port-channel

Misc

• Configure load balancing method:

switch01(config)# port-channel load-balance src-dst-port

EtherChannel on a Windows Server

EtherChannel can also be used with Windows Server. Here's an example of a server with two network interfaces.

Cisco switch configuration

• Configure switch01:

switch01(config)# interface range GigabitEthernet1/0/25-26
switch01(config-if)# switchport mode access
switch01(config-if)# switchport access vlan 2
switch01(config-if)# channel-protocol lacp
switch01(config-if)# channel-group 2 mode passive

• We can now configure EtherChannel interface like any other interface, using the name Po 2:

switch01(config)# interface port-channel 2

Windows Server configuration

⚠️ Please note that creating the NIC Teaming interface will delete the current network card configuration. Do not perform this operation from remote access, otherwise you may lose access to the server. ⚠️

Configuration from the GUI

• In the Server Manager, click on the NIC Teaming link:

• In the NIC Teaming window, create a NewTeam:

• Give the new interface a name, and define the teaming mode to LACP and Address Hash as the load balancing mode:

• Verify that everything is operational:

• In the Network Connections menu, define your team interface as any other network interface:

Configuration with PowerShell

• We can do the same thing with a PowerShell command line, which saves us a lot of time!:

PS C:\ > New-NetLBFOTeam -LoadBalancingAlgorithm IPAddresses -TeamingMode Lacp -Name NewTeam -TeamMembers Ethernet0,Ethernet1 -Confirm:$false

EtherChannel on a GNU/Linux Server

Cisco switch configuration

• Configure switch01:

switch01(config)# interface range GigabitEthernet1/0/25-26
switch01(config-if)# switchport mode access
switch01(config-if)# switchport access vlan 2
switch01(config-if)# channel-protocol lacp
switch01(config-if)# channel-group 2 mode active

• We can now configure the EtherChannel interface like any other interface, using the name Po 2:

switch01(config)# interface port-channel 2

Debian Server

• Install the ifenslave package, necessary to enable bonding:

root@host:~# apt-get install ifenslave

• Edit the /etc/network/interfaces file, and create the bond0 interface. Here with physical interfaces eth0 and eth1:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

auto bond0
iface bond0 inet static
    address 192.168.1.200
    netmask 255.255.255.0
    network 192.168.1.0
    gateway 192.168.1.254
    bond-slaves eth0 eth1
    #4 for LACP/802.3ad
    bond-mode 4
    #frequency of link status check in milliseconds
    bond-miimon 100
    bond-downdelay 200
    bond-updelay 200
    bond-lacp-rate fast
    #mac and ip
    bond-xmit-hash-policy layer2+3

• Restart the Debian server:

root@host:~# reboot

• Check that the bond0 interface is up:

root@host:~# ip address show dev bond0
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 72:17:b9:8d:1e:ad brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.200/24 brd 192.168.1.255 scope global bond0
       valid_lft forever preferred_lft forever
    inet6 fe80::7017:b9ff:fe8d:1ead/64 scope link 
       valid_lft forever preferred_lft forever

• Get information on the bond0 interface:

root@host:~# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v5.10.0-9-amd64

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2+3 (2)
II Status: up
II Polling Interval (ms): 100
Up Delay (ms): 200
Down Delay (ms): 200
Peer Notification Delay (ms): 0

802.3ad info
LACP rate: fast
in links: 0
Aggregator selection policy (ad_select): stable
System priority: 65535
System MAC address: 72:17:b9:8d:1e:ad
Active Aggregator Info:
        Aggregator ID: 1
        Number of ports: 1
        Actor Key: 15
        Partner Key: 1
        Partner Mac Address: 00:00:00:00:00:00

root@host:~# cat /sys/class/net/bond0/bonding/mode
802.3ad 4

References

• https://social.technet.microsoft.com/
• https://wiki.debian.org/