Configuring Port-Channel Interfaces and System and Port Parameters

Refer to Link Aggregation Topology figure for setup. Ports 1, 2 and 3 will be part of link aggregation and will be configured to belong to port-channel 1. Different system and port parameters will be configured.

  1. Enable LA, configure the physical port 24 in a port channel, and specify the mode as active.
    iS5comm(config)# set port-channel enable
    iS5comm(config)# interface port-channel 1
    iS5comm(config-if)# no shutdown
    iS5comm(config)# interface gigabitethernet 0/24
    iS5comm(config-if)# no shutdown
    iS5comm(config-if)# channel-group 1 mode active
    iS5comm(config)# end
  2. Configure the physical port 1 in a port channel, and specify the mode as active.
    iS5comm(config)# interface gigabitethernet 0/1
    iS5comm(config-if)# no shutdown
    iS5comm(config-if)# channel-group 1 mode active
    % LAG cannot be created for ports in Half Duplex mode
    iS5comm(config-if)# end
    iS5comm # show interface Gigabitethernet 0/1 status
    Port Status Duplex   Speed       Negotiation     Capability
    ---- ------ ------   -----       -----------     ----------
    Gi0/3 not connected Half     1 Gbps      Auto Auto-MDIX on

    Now, we check also the status of the other port we want to configure to belong to port-channel 1.

    iS5comm # show int gi 0/2 status
    Port Status Duplex   Speed       Negotiation     Capability
    ---- ------ ------   -----       -----------     ----------
    Gi0/3 not connected Half     1 Gbps      Auto Auto-MDIX on

    To troubleshoot, we will perform the following additional configuration:

    iS5comm(config)# interface gigabitethernet 0/1

    iS5comm(config-if)# duplex full
    % Duplexity cannot be set if auto-negotiation is enabled

    iS5comm(config-if)# no negotiation

    iS5comm(config-if)# duplex full

    iS5comm(config-if)# end

    iS5comm# show interface Gigabitethernet 0/1 status
    Port Status Duplex   Speed       Negotiation     Capability
    ---- ------ ------   -----       ----------- ----------
    Gi0/1 not connected    Full     1 Gbps      No-Negotiation  Auto-MDIX on

    Now, we perform the same configuration for port 2 as follows:

    iS5comm(config)# interface gigabitethernet 0/2

    iS5comm(config-if)# no negotiation

    iS5comm(config-if)# duplex full

    iS5comm(config-if)# end

    iS5comm# show interface Gigabitethernet 0/2 status
    Port Status Duplex   Speed       Negotiation     Capability
    ---- ------ ------   -----       ----------- ----------
    Gi0/2 not connected    Full     1 Gbps      No-Negotiation  Auto-MDIX on
  3. Configure the physical port 1 to be added to the port channel, and specify the mode as active.
    iS5comm(config)# interface gigabitethernet 0/1
    iS5comm(config-if)# no shutdown
    iS5comm(config-if)# channel-group 1 mode active
    iS5comm(config-if)# exit
  4. Configure the physical port 2 to be added to the port channel, and specify the mode as active.
    iS5comm(config)# interface gigabitethernet 0/2
    iS5comm(config-if)# no shutdown
    iS5comm(config-if)# channel-group 1 mode active
    iS5comm(config-if)# exit
  5. Exit from the Interface Configuration Mode.
    iS5comm(config)# end
  6. View the enabled Port-channel Interface.
    iS5comm(config)# show etherchannel detail
    Port-channel Module Admin Status is enabled
    Port-channel Module Oper Status is enabled
    Port-channel recovery action on exceeding Threshold is None
    Port-channel Independent mode is disabled
    Port-channel System Identifier is  e8:e8:75:90:5f:81
    LACP System Priority: 32768
    LACP Error Recovery Time: 0
    LACP Error Recovery Threshold: 5
    LACP Recovery Triggered count: 0
    LACP Error Recovery Threshold for Defaulted State : 5
    LACP Error Recovery Threshold for Hardware Failure : 5
    LACP Same state threshold : 5
                     Channel Group Listing 
    	---------------------
    Group: 1
    ----------
    Protocol :LACP
                     Ports in the Group 
    ------------------
    Port : Gi0/1
    -------------
    

    Port State = Down, Not in Bundle
    

    Reason for port-down : Oper status of the port is down
    

    Channel Group : 1
    

    Mode : Active
    

    Port-channel = Null
    

    Pseudo port-channel = Po1
    

    LACP port-priority  = 128
    

    LACP Wait-time  = 2 secs
    

    LACP Port Identifier = 1
    

    LACP Activity : Active
    

    LACP Timeout : Long
    

    LACP Error State : None
    

    

    Aggregation State : Aggregation, Defaulted
    

    

    Port : Gi0/2
    

    -------------
    

    

    Port State = Down, Not in Bundle
    

    Reason for port-down : Oper status of the port is down
    

    Channel Group : 1
    

    Mode : Active
    

    Port-channel = Null
    

    Pseudo port-channel = Po1
    

    LACP port-priority  = 128
    

    LACP Wait-time  = 2 secs
    

    LACP Port Identifier = 2
    

    LACP Activity : Active
    

    LACP Timeout : Long
    

    LACP Error State : None
    

    

    Aggregation State : Aggregation, Defaulted
    

    

    Port : Gi0/24
    

    -------------
    

    

    Port State = Up in Bundle
    

    Channel Group : 1
    

    Mode : ActivePort-channel = Po1
    

    Pseudo port-channel = Po1
    

    LACP port-priority  = 128
    

    LACP Wait-time  = 2 secs
    

    LACP Port Identifier = 24
    

    LACP Activity : Active
    

    LACP Timeout : Long
    

    LACP Error State : None
    

    

    Aggregation State : Aggregation, Sync, Collecting, Distributing, Defaulted
    

                     LACP Port   Admin  Oper   Port    Port
    

    Port     State   Priority    Key    Key    Number  State
    

    ---------------------------------------------------------------------
    

    Gi0/1    Down    128         1      1      0x1     0xa2
    

    Gi0/2    Down    128         1      1      0x2     0xa2
    

    Gi0/24   Bundle  128         1      1      0x18    0xbe
    

    

    Port-channel : Po1
    

    -------------------
    

    Number of Ports = 3
    

    HotStandBy port = null
    

    Port state = Port-channel Ag-Inuse
    

    Protocol = LACP
    

    Aggregator-MAC  e8:e8:75:90:5f:9d
    

    Maximum number of Ports  = 8
    

    

    Port-Channel Mtu         = 1500
    

    Port-Channel Speed       = 1000 Mbps
    

    Port-Channel High Speed  = 1000 Mbps
    

    Port-Channel Member Ports Speed = 1000 Mbps
    

    Port-Channel Member Ports High Speed  = 1000 Mbps
    

    7. 










Parent topic: LA Configuration






Configuring System Priority



Configure the priority of the system
for LACP. The higher the number,
the lower the priority. The valid range is from 1 to 65535, with
a default of 32768. The switch with the lower system priority value
determines the links between the LACP partner
switches that are in active and standby states for each LACP port-channel.

iS5comm(config)# lacp system-priority20









Configuring Port Priority



The port priority is used to decide which
ports should be put into standby mode when there is a hardware limitation
that prevents all compatible ports from aggregating.





Execute the following command to configure the LACP Port Priority, for Port 24
in Switch A.

iS5comm(config)# interface gigabitethernet 0/24


iS5comm(config-if)# lacp port-priority 20









Configuring Port-channel Load Balance



Traffic in a port-channel is distributed across
the individual bundled links in a deterministic fashion. However,
the load is not necessarily balanced equally across all links. Instead,
frames are forwarded on a specific link using any of the following
criteria - source IP address, destination IP address, or a combination of source
and destination IP addresses, source
and destination MAC addresses.


The
load-balance policy can be configured as:


  • src-mac: Load
distribution is based on the source MAC address
in the frame. Packets from different hosts use different ports in
the channel, but packets from the same host use the same port.
    • 


  • dest-mac: Load distribution is based on the destination MAC address in the frame. Packets
to the same destination are sent on the same port, but packets to
different destinations are sent on different ports in the channel.
    • 


  • src-dest-mac: Load distribution is based on the source and destination MAC addresses.
    • 


  • src-ip: Load distribution is based on the source IP address.
    • 


  • dest-ip: Load distribution is based on the destination IP address.
    • 


  • src-dest-ip: Load distribution is based on the source and destination IP addresses.
    • 


  • vlan-id: Load distribution is based on VLAN Identifier
    • 






Execute the following command to configure the LACP Port Priority, for Port 24
in Switch A.

iS5comm(config)# port-channel load-balance dest-mac









Configuring LACP System Identifier



Configure the LACP System Identifier.
This is an Unicast MAC address with a format of <aa:aa:aa:aa:aa:aa>.

iS5comm(config)# lacp system-identifier 00:55:44:33:22:11









Configuring LACP Port Identifier



Configure the Port Identifier. The value
is in the range of 1 to 65535.

iS5comm(config)# interface gigabitethernet 0/24


iS5comm(config-if)# lacp port-identifier 1


iS5comm(config)# end









Configuring LACP Wait time



LACP wait
time is the wait interval for a link to get aggregated. Configuring
the wait-time value as 0 ensures that links get aggregated immediately.
Default value of LACP wait time
is 2.





Execute the following commands to configure the LACP wait time.

iS5comm(config)# interface gigabitethernet 0/24


iS5comm(config-if)# lacp wait-time 1


iS5comm(config)# end









Configuring LACP Time-out



LACP time
out is a periodic interval, on expiry, LACP PDU is received regularly. Default
value of LACP time out is Long.


This
command configures the LACP timeout
period within which LACP PDUs are received on a port to avoid
timing out of aggregation link.


Note: 
The long timeout value
means that LACP PDU is received every 30 seconds
and LACP timeout value (no packet
is received from peer) is 90 seconds.




Note: 
The short
timeout value means that LACP PDU is received every 1 second and
timeout value is 3 seconds.







Execute the following commands to configure the LACP Timeout.

iS5comm(config)# interface gigabitethernet 0/24


iS5comm(config-if)# lacp timeout short


iS5comm(config)# end









Displaying Configured System and Port Parameters



View the configured system priority
and port priority.

iS5comm(config)# show etherchannel detail
Port-channel Module Admin Status is enabled


Port-channel Module Oper Status is enabled


Port-channel recovery action on exceeding Threshold is None


Port-channel Independent mode is disabled


Port-channel System Identifier is 00:55:44:33:22:11


LACP System Priority: 20


LACP Error Recovery Time: 0


LACP Error Recovery Threshold: 5


LACP Recovery Triggered count: 0


LACP Error Recovery Threshold for Defaulted State : 5


LACP Error Recovery Threshold for Hardware Failure : 5


LACP Same state threshold : 5


                 Channel Group Listing 


	---------------------


Group: 1


----------


Protocol :LACP


                 Ports in the Group 


------------------


Port : Gi0/1


-------------




Port State = Down, Not in Bundle


Reason for port-down : Oper status of the port is down


Channel Group : 1


Mode : Active


Port-channel = Null


Pseudo port-channel = Po1


LACP port-priority  = 128


LACP Wait-time  = 2 secs


LACP Port Identifier = 1


LACP Activity : Active


LACP Timeout : Long


LACP Error State : None




Aggregation State : Aggregation, Defaulted




Port : Gi0/2


-------------




Port State = Down, Not in Bundle


Reason for port-down : Oper status of the port is down


Channel Group : 1


Mode : Active


Port-channel = Null


Pseudo port-channel = Po1


LACP port-priority  = 128


LACP Wait-time  = 2 secs


LACP Port Identifier = 2


LACP Activity : Active


LACP Timeout : Long


LACP Error State : None




Aggregation State : Aggregation, Defaulted




Port : Gi0/24


-------------




Port State = Up in Bundle


Channel Group : 1


Mode : Active


Port-channel = Po1


Pseudo port-channel = Po1


LACP port-priority  = 20


LACP Wait-time  = 1 secs


LACP Port Identifier = 24


LACP Activity : Active


LACP Timeout : Short


LACP Error State : None




Aggregation State : Aggregation, Sync, Collecting, Distributing, Defaulted


                 LACP Port   Admin  Oper   Port    Port


Port     State   Priority    Key    Key    Number  State


---------------------------------------------------------------------


Gi0/1    Down    128         1      1      0x1     0xa2


Gi0/2    Down    128         1      1      0x2     0xa2


Gi0/24   Bundle  20          1      1      0x18    0xbe




Port-channel : Po1


-------------------


Number of Ports = 3


HotStandBy port = null


Port state = Port-channel Ag-Inuse


Protocol = LACP


Aggregator-MAC  e8:e8:75:90:5f:9d


Maximum number of Ports  = 8




Port-Channel Mtu         = 1500


Port-Channel Speed       = 1000 Mbps


Port-Channel High Speed  = 1000 Mbps


Port-Channel Member Ports Speed = 1000 Mbps


Port-Channel Member Ports High Speed  = 1000 Mbps









Saving Port-channel and LACP Configuration



To save the configuration after reboot
of the devices.

iS5comm# write startup-config