Link Aggregation Group (LAG)
LAG implementation is compliant with 802.1AX standard.
Link Aggregation Group (LAG) protocol describes a network operation in which several same speed links are combined into a single logical entity with the accumulated bandwidth of the originating ports. LAG groups exchange Lag Aggregation Control Protocol (LACP) packets in order to align the functionality between both endpoints of the LAG. To equally send traffic on all LAG links, the switch uses a hash function which can use a set of attributes as key to the hash function.
As many as 32 physical ports can be aggregated on a single LAG.
Create a port-channel entity.
switch
(config) #interface
port-channel1
switch
(configinterface
port-channel1
) #Change back to config mode.
switch
(configinterface
port-channel1
) # exitswitch
(config) #Add a physical port to the LAG.
switch
(configinterface
ethernet1
/4
) # channel-group1
mode onswitch
(configinterface
ethernet1
/4
) #WarningIf the physical port is operationally up, this port becomes an active member of the aggregation. Consequently, it becomes able to convey traffic.
Create a port-channel entity.
switch
(config) #interface
port-channel1
switch
(configinterface
port-channel1
) #Change back to config mode.
switch
(configinterface
port-channel1
) # exitswitch
(config) #Enable LACP in the switch.
switch
(config) # lacpAdd a physical port to the LAG.
switch
(configinterface
ethernet1
/4
) # channel-group1
mode activeOr:
switch
(configinterface
ethernet1
/4
) # channel-group1
mode passive
For more information about this feature and its potential applications, please refer to the following community posts:
interface port-channel
interface port-channel <1-4096>[-<2-4096>] Creates a LAG and enters the LAG configuration mode. There is an option to create a range of LAG interfaces. | ||
Syntax Description | 1-4096 / 2-4096 | LAG number |
Default | N/A | |
Configuration Mode | config | |
History | 3.1.1400 | |
3.2.1100 | Added range support | |
Example | switch (config)# interface port-channel 1 | |
Related Commands | show interface port-channel | |
Notes |
|
lacp
lacp Enables LACP in the switch. | ||
Syntax Description | N/A | |
Default | LACP is disabled | |
Configuration Mode | config | |
History | 3.1.1400 | |
Example | switch (config)# lacp | |
Related Commands | ||
Notes |
lacp system-priority
lacp system-priority <1-65535> Configures the LACP system priority. | ||
Syntax Description | 1-65535 | LACP system-priority |
Default | 32768 | |
Configuration Mode | config | |
History | 3.1.1400 | |
Example | switch (config)# lacp system-priority 1 | |
Related Commands | show lacp interfaces port-channel | |
Notes | Each device that runs LACP has an LACP system priority value. A value between 1 and 65535 can be configured. LACP uses the system priority with the MAC address to form the system ID. When setting the priority, a higher number means a lower priority. |
lacp (interface)
lacp {rate fast | port-priority <1-65535>} Configures the LACP interface parameters. | ||
Syntax Description | rate fast | Sets LACP PDUs on the port to be in fast (1 second) or slow rate (30 seconds) |
1-65535 | LACP port-priority | |
Default | rate—slow (30 seconds) | |
Configuration Mode | config interfaces ethernet | |
History | 3.1.1400 | |
Example | switch (config interfaces ethernet 1/7)# lacp rate fast | |
Related Commands | ||
Notes | Configuring LACP rate (fast or slow) will configure the peer port to send (fast or slow), it does not make any affect on the local port LACP rate. |
port-channel load-balance ethernet
port-channel load-balance ethernet {<method> | [symmetric]} Configures the port-channel load balancing distribution function method, with symmetric hashing enabled or not. | |||
Syntax Description | method | destination-ip | Destination IP address |
destination-mac | Destination MAC address | ||
destination-port | Destination UDP/TCP port | ||
flow-label | IPv6 flow-label field | ||
l2-protocol | Ethertype field | ||
l3-protocol | IP protocol field | ||
ingress-port | Ingress port | ||
source-destination-ip | Source and destination IP addresses | ||
source-destination-mac | Source and destination MAC addresses | ||
source-destination-port | Source and destination UDP/TCP ports | ||
source-ip | Source IP address | ||
source-mac | Source MAC address | ||
source-port | Source UDP/TCP port | ||
symmetric | Symmetric hashing; bidirectional flows follow same path | ||
symmetric | Enables symmetric hashing | ||
Default | source-destination-mac, source-destination-ip, source-destination-port, l3-protocol, l2-protocol, flow-label | ||
Configuration Mode | config | ||
History | 3.1.1400 | ||
3.8.1000 | Updated syntax | ||
3.8.2100 | Changed the method options. Modified default LAG HASH to support TCP/UDP ports. | ||
Example | switch (config) # port-channel load-balance ethernet ? destination-ip Destination IP address ingress-port Ingress port | ||
Related Commands | show interface port-channel load-balance | ||
Notes |
|
channel-group
channel-group <1-4096> [mode {on | active | passive}] Assigns and configures a physical interface to a LAG. | ||
Syntax Description | 1-4096 | The port channel number |
mode on | Static assignment the port to LAG. LACP will not be enabled on this port. | |
mode active/passive | Dynamic assignment of the port to LAG. LACP will be enabled in either passive or active mode. | |
Default | N/A | |
Configuration Mode | config interface ethernet | |
History | 3.1.1400 | |
3.4.0008 | Added a note | |
3.6.3640 | Added a note | |
3.6.4006 | Added a note | |
Example | switch (config interface ethernet 1/7) # channel-group 1 mode active | |
Related Commands | show interfaces port-channel summary | |
Notes |
|
lacp-individual enable
lacp-individual enable [force] Configures the LAG to act with LACP-individual capabilities. | ||
Syntax Description | force | Toggles the interface after enabling LACP-individual |
Default | N/A | |
Configuration Mode | config interface port-channel | |
History | 3.4.1100 | |
Example | switch (config interface port-channel 10) # lacp-individual enable force | |
Related Commands | ||
Notes | If a switch is connected via LAG to a host without LACP capability, running this command on that LAG allows a member port (with the lowest numerical priority value), acting as an individual, to communicate with the host |
ip address dhcp
ip address dhcp Enables DHCP on this LAG interface. | ||
Syntax Description | N/A | |
Default | Disabled | |
Configuration Mode | config interface port-channel set as router interface | |
History | 3.4.2008 | |
Example | switch (config interface port channel 10) # ip address dhcp | |
Related Commands | interface port-channel | |
Notes |
show lacp counters
show lacp counters Displays the LACP PDUs counters. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | config interface port-channel set as router interface | |
History | 3.1.1400 | |
3.6.6000 | Updated example | |
Example | ||
switch (config) # show lacp counters Port-channel 5: | ||
Related Commands | interface port-channel | |
Notes |
show lacp interfaces ethernet
show lacp interface ethernet <inf> Displays the LACP interface configuration and status. | ||
Syntax Description | inf | Interface number (e.g., “1/1”) |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.1.1400 | |
3.6.6102 | Updated example | |
Example | ||
switch (config) # show lacp interfaces ethernet 1/1 | ||
Related Commands | ||
Notes |
show lacp interfaces neighbor
show lacp interfaces neighbor Displays the LACP interface neighbor status. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.1.1400 | |
3.4.0000 | Updated example | |
Example | ||
| ||
Related Commands | ||
Notes |
show lacp
show lacp Displays the LACP global parameters. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.4.0000 | |
Example | switch (config) # show lacp | |
Related Commands | ||
Notes |
show lacp interfaces system-identifier
show lacp interfaces {mlag-port-channel | port-channel} <instance> system-identifier Displays the system identifier of LACP. | ||
Syntax Description | instance | LAG or MLAG instance |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.4.0000 | |
Example | switch (config)# show lacp interfaces port-channel 2 system-identifier | |
Related Commands | ||
Notes |
show interfaces port-channel
show interfaces port-channel <port-channel> Displays LAG configuration properties. | ||
Syntax Description | port-channel | LAG interface whose properties to display |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.3.4000 | |
3.4.1100 | Updated example | |
3.6.1002 | Added “error packets” counter to Tx | |
3.6.5000 | Updated example with telemetry | |
3.6.8008 | Updated example | |
3.7.1000 | Updated example | |
3.9.1000 | Updated example | |
Example | ||
switch (config) # show interfaces port-channel 10
| ||
Related Commands | ||
Notes |
show interfaces port-channel counters
show interfaces port-channel <port-channel> counters Displays the extended counters for the interface. | ||
Syntax Description | port-channel | LAG interface whose properties to display. |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.6.1002 | |
3.9.1000 | Added ability to use a range of ports | |
Example |
Po3: . . . | |
Related Commands | ||
Notes | As of version 3.9.1000, the "port-channel" attribute is optional. If nothing is selected, information for all ports will be displayed |
show interfaces port-channel compatibility-parameters
show interfaces port-channel compatibility-parameters Displays LAG parameters. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.3.4000 | |
3.6.3640 | Added “forwarding mode” as compatibility parameter to output | |
3.6.6000 | Updated example | |
3.6.8008 | Updated example | |
Example |
| |
Related Commands | ||
Notes |
show interfaces port-channel load-balance
show interfaces port-channel load-balance Displays the type of load-balancing in use for LAGs. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.3.4000 | |
Example |
| |
Related Commands | port-channel load-balance ethernet ? | |
Notes |
show interfaces port-channel summary
show interfaces port-channel summary Displays a summary for LAG interfaces. | ||
Syntax Description | N/A | |
Default | N/A | |
Configuration Mode | Any command mode | |
History | 3.1.1400 | |
3.4.1100 | Updated example | |
Example | ||
switch (config) # show interfaces port-channel summary
| ||
Related Commands | ||
Notes |