Link Aggregation Management on ESW2-350G Switches

Objective

Link Aggregation Control Protocol (LACP) is a part of IEEE specification (802.3ad) that can control the bundling of several physical ports together to form a single logical channel (LAG). Traffic load balancing over the active member ports of a LAG is managed by a hash-based distribution function that distributes unicast and multicast traffic based on Layer 2 or Layer 3 packet header information. LAGs help in bandwidth multiplication, increase in port flexibility, and in providing redundancy on links between any 2 devices and LACP helps in changing the LAG speed, advertisement, flow control and protection. This protocol can be used to set a logical link between two adjacent LACP enabled devices. These two devices can have multiple physical links between them.

This document explains how to select the load balancing algorithm, how to define a member or candidate port on the LAG, how to configure LAG settings, and how to reactivate a suspended LAG on the ESW2-350G Switches.

Applicable Devices

• ESW2-350G
• ESW2-350G-DC

Software Version

• v1.2.9.44

LAG Management Procedure

Step 1. Log in to the switch configuration utility and choose Port Management > Link Aggregation > LAG Management. The LAG Management page opens.

 

Step 2. Click one of the following radio buttons for the Load Balance Algorithm.

• MAC Address — Performs load balancing by source and destination MAC addresses on all the packets.

• IP/MAC Address — Performs load balancing by the source and destination IP addresses on IP packets, and by the source and destination MAC addresses on non-IP packets.

Step 3. Click the Apply button to apply the changes and the Running Configuration file is updated.

The description of the fields in the LAG Management Table are as follows.

• LAG — LAGs are shown in the column.

• Name — LAG name configured is shown in the column.

• LACP — Shows whether LACP is enabled or disabled to the particular LAG.

• Link State — Shows whether the LINK of the LAG is active or down.

• Active Member — Shows the member which are in the field and are active in the configured set.

• Standby Member —  Shows the members which are configured to the LAG members which are on standby.

Step 4. To define member or candidate ports in the LAG Management Table, click the radio button of the desired LAG to be configured and click Edit. The Edit LAG Membership window appears.

Step 5. Choose the LAG number from the LAG drop-down list.

 

Step 6. Enter a name for the LAG in the LAG Name field.

Step 7. Check the Enable check box in the LACP field to enable the dynamic LAG. Dynamic LAG uses LACP packets to establish connection between the two peers.

Note: Static LAG is a group of links aggregated where there is no signaling between the two peers and therefore a misconfiguration on one side may lead to harmful effects (such as a link mismatch). A dynamic LAG uses LACP packets to establish a connection between the two peers. At least one side of the connection needs to be configured in Dynamic LAG. 

 

Step 8. Move the ports that are to be assigned to the LAG from the Port List to the LAG Members list. Up to eight ports to static LAG and 16 ports to a dynamic LAG can be assigned. If LACP is enabled on the LAG then it is a dynamic LAG.

Step 9. Click Apply to save the changes in the Edit LAG Membership page.

Configure LAG Settings (or) Reactivate Suspended LAG

Step 1. Log in to the switch configuration utility and choose Port Management > Link Aggregation > LAG Settings.The LAG Settings page opens.

 

Step 2. Click the LAG that needs to be modified and then click Edit. 

Step 3. The Edit LAG Settings window appears.

 

Configure the following fields:

• LAG — Choose the LAG ID number from the drop-down list.

• Description — Enter the LAG name or a comment.

• LAG Type — Displays the port type that comprises the LAG.

• Administrative Status — Click the selected LAG to be Up or Down. Up means the link is active and down means the link is not active.

• Reactivate Suspended LAG — Check to reactivate a port if the LAG has been disabled through the locked port security option or through ACL configurations.

• Operational Status — Displays whether the LAG is currently operating.

• Administrative Auto Negotiation — Check this field to enable or disable auto-negotiation on the LAG. Auto-negotiation is a protocol between two link partners that enables a LAG to advertise its transmission speed and flow control to its partner (the Flow Control default is disabled).

Note: It is recommended to keep auto-negotiation enabled on both sides of an aggregate link, or disabled on both sides, while ensuring that link speeds are identical.

• Operational Auto Negotiation — Displays the auto-negotiation setting.

• Administrative Speed — Click any of the 3 LAG speed which are available. The available speeds are: 10M, 100M and 1000M.

Note: When auto negotiation is enabled, by default 10M is selected.

• Operational LAG Speed — Displays the current speed at which the LAG is operating.

• Administrative Advertisement — Check the capabilities to be advertised by the LAG. The options are:

– Max Capability — All LAG speeds and both Full duplex and half duplex modes are available. Full duplex means that the interface supports transmission between the device and its link partner in both directions simultaneously. Half duplex means that the interface supports transmission between the device and the client in only one direction at a time.

– 10 Full — The LAG advertises a 10 Mbps speed and the mode is full duplex.

– 100 Full — The LAG advertises a 100 Mbps speed and the mode is full duplex.

– 1000 Full — The LAG advertises a 1000 Mbps speed and the mode is full duplex.

• Operational Advertisement — Displays the Administrative Advertisement status. The LAG advertises its capabilities to its neighbor LAG to start the negotiation process. The possible values are those specified in the Administrative Advertisement field.

• Administrative Flow Control — Flow control should be enabled to control network traffic during periods of congestion and prevent the loss of packets when port buffer thresholds are exceeded. Click Enable, Disable or Auto-Negotiation of Flow Control on the LAG.

– Enable — This option allows the switch to advertise the 802.3x format frames.

– Disable — This option to disables flow control.

– Auto-Negotiation — Enables Auto Negotiation on the port. Auto Negotiation is a protocol between two link partners that enables a port to advertise its transmission rate, duplex mode and flow control abilities to its partner.

• Operational Flow Control — Displays the current Flow Control setting.

• Protected LAG — Check to make the LAG a protected port for Layer 2 isolation. See the Port Configuration description in the Setting Basic Port Configuration section for details regarding protected ports and LAG's.

Step 4. Click Apply. The Running Configuration file is updated.

Step 5. (Optional) Click Copy Settings... to copy the settings of a LAG to another LAG member.

Step 6. (Optional) Enter the LAG number value to which it needs to be copied in the to: field.

LACP Configuration

Step 1. Choose Port Management > Link Aggregation > LACP from the switch configuration utility. The LACP page opens:

Note: LACP System Priority is different from LACP Port priority but LACP system priority and LACP port priority are both used to determine which of the candidate ports become active member ports in a dynamic LAG configured with more than eight candidate ports.

Step 2. Enter the LACP system priority value in the LACP System Priority. The device with lowest system priority value controls candidate port selection to the LAG. If both the priorities are same then the MAC address of the local and remote device are compared and lowest MAC address controls candidate port selection to the LAG.

Step 3. Click Apply.

Step 4. Click the radio button corresponding to the desired interface to edit and then click the Edit button.The Edit LACP window opens.

 

Step 5. Choose the appropriate port number from the Port drop-down list for which the port priority and timeout values are to be set.

Step 6. Enter the LACP port priority value for the particular port in the LACP Port Priority field. Port with lowest priority is more likely to be in the active stand than the high priority one.

Step 7. Click either of LACP Timeout radio buttons to set whether the interval between retransmissions is long or short. Long time out would be 90 seconds and short time out would be 3 seconds by default.

Step 8. Click Apply.

Step 9. (Optional) Click Copy Settings... to copy the settings of a port interface  to another Port interface.

Step 10. (Optional) Enter the Port number to which it needs to be copied in the to: field.