· Improved link reliability. The member ports dynamically back up one another. When a member port fails, its traffic is automatically switched to other member ports.

As shown in Figure 1, Device A and Device B are connected by three physical Ethernet links. These physical Ethernet links are combined into an aggregate link called link aggregation 1. The bandwidth of this aggregate link can reach up to the total bandwidth of the three physical Ethernet links. At the same time, the three Ethernet links back up one another. When a physical Ethernet link fails, the traffic previously transmitted on the failed link is switched to the other two links.

Figure 1 Ethernet link aggregation diagram

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Aggregation group, member port, and aggregate interface

An aggregation group is a group of Ethernet interfaces bundled together. These Ethernet interfaces are called member ports of the aggregation group. Each aggregation group has a corresponding logical interface (called an aggregate interface).

When an aggregate interface is created, the device automatically creates an aggregation group of the same type and number as the aggregate interface.

An aggregate interface can be one of the following types:

· Layer 2—A Layer 2 aggregate interface is created manually. The member ports of the corresponding Layer 2 aggregation group can only be Layer 2 Ethernet interfaces.

On an IRF 3.1 system, an aggregation group is called a Layer 2 extended-link aggregation group if its member ports are on PEXs. The logical interface of the aggregation group is called a Layer 2 extended-link aggregate interface. For more information about PEXs, see IRF 3.1 configuration in Virtual Technologies Configuration Guide.

· Layer 3—A Layer 3 aggregate interface is created manually. The member ports of the corresponding Layer 3 aggregation group can only be Layer 3 Ethernet interfaces.

On a Layer 3 aggregate interface, you can create subinterfaces. A Layer 3 aggregate subinterface processes traffic only for the VLAN numbered with the same ID as the subinterface number.

Do not use the VLAN whose ID matches a Layer 3 aggregate subinterface number.

The port rate of an aggregate interface equals the total rate of its Selected member ports. Its duplex mode is the same as that of the Selected member ports. For more information about Selected member ports, see "Aggregation states of member ports in an aggregation group."

Aggregation states of member ports in an aggregation group

A member port in an aggregation group can be in any of the following aggregation states:

· Selected—A Selected port can forward traffic.

· Unselected—An Unselected port cannot forward traffic.

· Individual—An Individual port can forward traffic as a normal physical port. This state is peculiar to the member ports of edge aggregate interfaces. A member port is placed in Individual state if it has not received LACPDUs before the first expiration of the LACP timeout timer after either of the following event occurs:

¡ The aggregate interface is configured as an edge aggregate interface.

¡ The member port goes down and then comes up after it is placed in Unselected or Selected state.

For more information about edge aggregate interfaces, see "Edge aggregate interface."

Operational key

When aggregating ports, the system automatically assigns each port an operational key based on port information, such as port rate and duplex mode. Any change to this information triggers a recalculation of the operational key.

In an aggregation group, all Selected ports have the same operational key.

Configuration types

Port configurations include attribute configurations and protocol configurations. Attribute configurations of a link aggregation member port affect its aggregation state.

· Attribute configurations—To become a Selected port, a member port must have the same attribute configurations as the aggregate interface. Table 1 describes the attribute configurations.

For a link aggregation, attribute configurations are configurable only on the aggregate interface and are automatically synchronized to all member ports. You cannot configure attribute configurations on a member interface until it is removed from the link aggregation group. The configurations that have been synchronized from the aggregate interface are retained on the member ports even after the aggregate interface is deleted.

If an attribute setting on the aggregate interface fails to be synchronized to a Selected member port, the port might change to the Unselected state.

Table 1 Attribute configurations

Feature	Considerations
Port isolation	Indicates whether the port has joined an isolation group and which isolation group the port belongs to.
QinQ	QinQ status (enabled/disabled), TPID for VLAN tags, and VLAN transparent transmission. For information about QinQ, see "Configuring QinQ."
VLAN mapping	VLAN mapping configured on the port. For more information about VLAN mapping, see "Configuring VLAN mapping."
VLAN	VLAN attribute configurations include the following: · Permitted VLAN IDs. · PVID. · Link type (trunk, hybrid, or access). · PVLAN port type (promiscuous, trunk promiscuous, host, or trunk secondary). · IP subnet-based VLAN configuration. · Protocol-based VLAN configuration. · VLAN tagging mode. For information about VLANs, see "Configuring VLANs."

· Protocol configurations—Settings that do not affect the aggregation state of a member port even if they are different from those on the aggregate interface. MAC address learning settings are examples of protocol configurations.

For an aggregation, only the protocol configurations on the aggregate interface take effect. The protocol configurations on the member ports will not take effect until after the ports leave the aggregation group.

Link aggregation modes

An aggregation group operates in one of the following modes:

· Static—Static aggregation is stable. An aggregation group in static mode is called a static aggregation group. The aggregation states of the member ports in a static aggregation group are not affected by the peer ports.

· Dynamic—An aggregation group in dynamic mode is called a dynamic aggregation group. The local system and the peer system automatically maintain the aggregation states of the member ports. Dynamic link aggregation reduces the administrators' workload.

Layer 2 aggregation groups and Layer 3 aggregation groups support both the static and dynamic modes.

How static link aggregation works

Reference port selection process

When setting the aggregation states of the ports in an aggregation group, the system automatically chooses a member port as the reference port. A Selected port must have the same operational key and attribute configurations as the reference port.

The system chooses a reference port from the member ports in up state.

The candidate reference ports are organized into different priority levels following these rules:

1. In descending order of port priority.

2. Full duplex.

3. In descending order of speed.

4. Half duplex.

5. In descending order of speed.

From the candidate ports with the same attribute configurations as the aggregate interface, the one with the highest priority level is chosen as the reference port.

· If multiple ports have the same priority level, the port that has been Selected (if any) is chosen. If multiple ports with the same priority level have been Selected, the one with the smallest port number is chosen.

· If multiple ports have the same priority level and none of them has been Selected, the port with the smallest port number is chosen.

NOTE:

To identify the port numbers of aggregation member ports, execute the display link-aggregation verbose command and examine the Index field in the command output.

Setting the aggregation state of each member port

After the reference port is chosen, the system sets the aggregation state of each member port in the static aggregation group.

Figure 2 Setting the aggregation state of a member port in a static aggregation group

After the limit on Selected ports is reached, the aggregation state of a new member port varies by following conditions:

· The port is placed in Unselected state if the port and the Selected ports have the same port priority. This mechanism prevents traffic interruption on the existing Selected ports. A device reboot can cause the device to recalculate the aggregation states of member ports.

· The port is placed in Selected state when the following conditions are met:

¡ The port and the Selected ports have different port priorities, and the port has a higher port priority than a minimum of one Selected port.

¡ The port has the same attribute configurations as the aggregate interface.

Any operational key or attribute configuration change might affect the aggregation states of link aggregation member ports.

Dynamic link aggregation

LACP

Dynamic aggregation is implemented through IEEE 802.3ad Link Aggregation Control Protocol (LACP).

LACP uses LACPDUs to exchange aggregation information between LACP-enabled devices. Each member port in a dynamic aggregation group can exchange information with its peer. When a member port receives an LACPDU, it compares the received information with information received on the other member ports. In this way, the two systems reach an agreement on which ports are placed in Selected state.

LACP functions

LACP offers basic LACP functions and extended LACP functions, as described in Table 2.

Table 2 Basic and extended LACP functions

Category	Description
Basic LACP functions	Implemented through the basic LACPDU fields, including the LACP system priority, system MAC address, port priority, port number, and operational key.
Extended LACP functions	Implemented by extending the LACPDU with new TLV fields. Extended LACP can implement LACP MAD for the IRF feature. If a device supports both extended LACP and IRF, it can participate in LACP MAD as either an IRF member device or an intermediate device. For more information about IRF and the LACP MAD mechanism, see Virtual Technologies Configuration Guide.

LACP operating modes

LACP can operate in active or passive mode.

When LACP is operating in passive mode on a local member port and its peer port, both ports cannot send LACPDUs. When LACP is operating in active mode on either end of a link, both ports can send LACPDUs.

LACP priorities

LACP priorities include LACP system priority and port priority, as described in Table 3. The smaller the priority value, the higher the priority.

Table 3 LACP priorities

Type	Description
LACP system priority	Used by two peer devices (or systems) to determine which one is superior in link aggregation. In dynamic link aggregation, the system that has higher LACP system priority sets the Selected state of member ports on its side. The system that has lower priority sets the aggregation state of local member ports the same as their respective peer ports.
Port priority	Determines the likelihood of a member port to be a Selected port on a system. A port with a higher port priority is more likely to become Selected.

Type

Description

LACP system priority

Used by two peer devices (or systems) to determine which one is superior in link aggregation.

In dynamic link aggregation, the system that has higher LACP system priority sets the Selected state of member ports on its side. The system that has lower priority sets the aggregation state of local member ports the same as their respective peer ports.

Port priority

Determines the likelihood of a member port to be a Selected port on a system. A port with a higher port priority is more likely to become Selected.

LACP timeout interval

The LACP timeout interval specifies how long a member port waits to receive LACPDUs from the peer port. If a local member port has not received LACPDUs from the peer within the LACP timeout interval, the member port considers the peer as failed.

The LACP timeout interval also determines the LACPDU sending rate of the peer. LACP timeout intervals include the following types:

· Short timeout interval—3 seconds. If you use the short timeout interval, the peer sends one LACPDU per second.

· Long timeout interval—90 seconds. If you use the long timeout interval, the peer sends one LACPDU every 30 seconds.

Methods to assign interfaces to a dynamic link aggregation group

You can use one of the following methods to assign interfaces to a dynamic link aggregation group:

· Manual assignment—Manually assign interfaces to the dynamic link aggregation group.

· Automatic assignment—Enable automatic assignment on interfaces to have them automatically join a dynamic link aggregation group depending on the peer information in the received LACPDUs.

NOTE:

When you use automatic assignment on one end, you must use manual assignment on the other end.

Automatic member interface assignment

As shown in Figure 3, an interface enabled with automatic assignment joins a dynamic aggregation group based on the peer information in the LACPDUs received from the aggregation peer. If none of the existing dynamic aggregation groups is qualified, the device automatically creates a new dynamic aggregation group, Then, the device assigns the interface to that group and synchronizes the interface's attribute configurations to the aggregate interface.

A dynamic aggregation group that contains automatically assigned member ports selects a reference port and Selected ports as described in "How dynamic link aggregation works." The assignment methods of member ports do not change the processes of reference port selection and Selected port selection.

Figure 3 Automatic member interface assignment process

Automatic link aggregation

Automatic link aggregation enables two devices to automatically create a dynamic link aggregation between them by using LLDP.

After you enable automatic link aggregation and LLDP on two connected devices, they automatically establish a dynamic link aggregation based on the information in incoming LLDP frames. The devices each automatically create a dynamic aggregate interface and assign the redundant ports connected to the peer to the aggregation group of that interface. When assigning the first member port to the aggregate group, the device synchronizes the member port's attribute configuration to the aggregate interface.

An automatically created dynamic aggregation group selects a reference port and Selected ports as described in "How dynamic link aggregation works." The aggregation group creation methods do not change the processes of reference port selection and Selected port selection.

IMPORTANT:

As a best practice to ensure correct operation of dynamic aggregation groups, do not use automatic link aggregation and automatic member port assignment together.

How dynamic link aggregation works

Choosing a reference port

The system chooses a reference port from the member ports in up state. A Selected port must have the same operational key and attribute configurations as the reference port.

The local system (the actor) and the peer system (the partner) negotiate a reference port by using the following workflow:

1. The two systems determine the system with the smaller system ID.

A system ID contains the LACP system priority and the system MAC address.

a. The two systems compare their LACP priority values.

The lower the LACP priority, the smaller the system ID. If the LACP priority values are the same, the two systems proceed to step b.

b. The two systems compare their MAC addresses.

The lower the MAC address, the smaller the system ID.

2. The system with the smaller system ID chooses the port with the smallest port ID as the reference port.

A port ID contains a port priority and a port number. The lower the port priority, the smaller the port ID.

a. The system chooses the port with the lowest priority value as the reference port.

If the ports have the same priority, the system proceeds to step b.

b. The system compares their port numbers.

The smaller the port number, the smaller the port ID.

The port with the smallest port number and the same attribute configurations as the aggregate interface is chosen as the reference port.

Setting the aggregation state of each member port

After the reference port is chosen, the system with the smaller system ID sets the state of each member port on its side.

Figure 4 Setting the state of a member port in a dynamic aggregation group

The system with the greater system ID can detect the aggregation state changes on the peer system. The system with the greater system ID sets the aggregation state of local member ports the same as their peer ports.

When you aggregate interfaces in dynamic mode, follow these guidelines:

· A dynamic link aggregation group chooses only full-duplex ports as the Selected ports.

· For stable aggregation and service continuity, do not change the operational key or attribute configurations on any member port.

· After the Selected port limit is reached, a newly joining port becomes a Selected port if it is more eligible than a current Selected port.

Edge aggregate interface

Dynamic link aggregation fails on a server-facing aggregate interface if dynamic link aggregation is configured only on the device. The device forwards traffic by using only one of the physical ports that are connected to the server.

To improve link reliability, configure the aggregate interface as an edge aggregate interface. This feature enables all member ports of the aggregation group to forward traffic. When a member port fails, its traffic is automatically switched to other member ports.

After dynamic link aggregation is configured on the server, the device can receive LACPDUs from the server. Then, link aggregation between the device and the server operates correctly.

An edge aggregate interface takes effect only when it is configured on an aggregate interface corresponding to a dynamic aggregation group.

Load sharing modes for link aggregation groups

In a link aggregation group, traffic can be load shared across the Selected ports based on any of the following modes:

· Per-flow load sharing—Distributes traffic on a per-flow basis. The load sharing mode classifies packets into flows and forwards packets of the same flow on the same link. This mode can be one or any combination of the following traffic classification criteria:

¡ Ingress port.

¡ Source or destination IP address.

¡ Source or destination MAC address.

¡ Source or destination port number.

¡ MPLS label.

· Packet type-based load sharing—Distributes traffic automatically based on packet types (Layer 2 protocol, IPv4, MPLS, or IPv6).

NOTE:

If the source or destination MAC address criterion is specified, the device automatically takes the VLAN tag into account when it distributes traffic across the Selected ports.

S-MLAG

Simple multichassis link aggregation (S-MLAG) enhances dynamic link aggregation to establish an aggregation that spans multiple devices to a remote device.

An S-MLAG multichassis aggregation connects one dynamic Layer 2 aggregate interface on each S-MLAG device to the remote device, as shown in Figure 5.

S-MLAG uses an S-MLAG group to manage the aggregate interfaces for each aggregation, and it runs LACP to maintain each aggregation as does dynamic link aggregation. To the remote device, the S-MLAG devices appear as one peer aggregation system.

Figure 5 S-MLAG application scenario

Configuration restrictions and guidelines

The device supports a maximum of 128 aggregation groups and a maximum of 8 member ports per group if the device contains any of the following modules:

· EA interface modules

· EB interface modules

· SC interface module: LSU1TGS16SC0

· SE interface modules:

¡ LSU1GP24TSE0

¡ LSU1GP24TXSE0

¡ LSU1GP48SE0

¡ LSU1GT48SE0

¡ LSU1TGS8SE0

¡ LSU1TGX4SE0

· OAP modules:

¡ LSU1FWCEA0

¡ LSU3FWCEA0

¡ LSU3WCMD0

On a device that contains the modules listed above, you can configure more aggregation groups and member ports per group if no aggregation member ports are on those modules. However, you must avoid doing so because this might result in traffic forwarding issues.

If the device does not contain any of the modules listed above, the device supports a maximum of 1000 aggregation groups and 32 member ports per group.

Ethernet link aggregation configuration task list

Tasks at a glance
(Required.) Configuring link aggregations: · Configuring a manual link aggregation · Configuring automatic link aggregation · Configuring S-MLAG
(Optional.) Configuring an aggregate interface: · Configuring the description of an aggregate interface · Configuring a dynamic aggregation group to use port speed as the prioritized criterion for reference port selection · Specifying ignored VLANs for a Layer 2 aggregate interface · Setting the MTU for a Layer 3 aggregate interface · Setting the minimum and maximum numbers of Selected ports for an aggregation group · Setting the expected bandwidth for an aggregate interface · Configuring an edge aggregate interface · Shutting down an aggregate interface · Restoring the default settings for an aggregate interface
(Optional.) Disabling the default action of selecting a Selected port for dynamic aggregation groups that have not received LACPDUs
(Optional.) Configuring load sharing for link aggregation groups: · Setting load sharing modes for link aggregation groups · Enabling local-first load sharing for link aggregation
(Optional.) Enabling BFD for an aggregation group

Configuring a manual link aggregation

Configuration restrictions and guidelines

The following information describes restrictions and guidelines that you must follow when you configure link aggregations.

Aggregation member interface restrictions

· You cannot assign an interface to a Layer 2 aggregation group if any features in Table 4 are configured on the interface.

Table 4 Features incompatible with Layer 2 aggregation member interfaces

Feature on the interface	Reference
MAC authentication	MAC authentication in Security Configuration Guide
Port security	Port security in Security Configuration Guide
802.1X	802.1X in Security Configuration Guide
Service instance bound to a cross connect	MPLS L2VPN in MPLS Configuration Guide
Service instance bound to a VSI	VPLS in MPLS Configuration Guide

· You cannot assign an interface to a Layer 3 aggregation group if any features in Table 5 are configured on the interface.

Table 5 Features incompatible with Layer 3 aggregation member interfaces

Feature on the interface	Reference
Interface bound to a cross connect	MPLS L2VPN in MPLS Configuration Guide
Interface bound to a VSI	VPLS in MPLS Configuration Guide

· Do not assign a reflector port for port mirroring to an aggregation group. For more information about reflector ports, see Network Management and Monitoring Configuration Guide.

· An interface cannot join an aggregation group if it has different attribute configurations from the aggregate interface. After joining an aggregation group, an interface inherits the attribute configurations on the aggregate interface. You can modify the attribute configurations only on the aggregate interface.

· A Layer 2 extended-link aggregation group can contain only extended ports that are on the same PEX or on the same-tier PEXs in the same PEX group. In the latter case, the PEXs must belong to the same series.

Configuration consistency requirements

· You must configure the same aggregation mode at the two ends of an aggregate link.

· For a successful static aggregation, make sure the ports at both ends of each link are in the same aggregation state.

· For a successful dynamic aggregation:

¡ Make sure the ports at both ends of a link are assigned to the correct aggregation group. The two ends can automatically negotiate the aggregation state of each member port.

¡ If you use automatic interface assignment method on one end, you must use manual assignment on the other end.

Miscellaneous

Deleting an aggregate interface also deletes its aggregation group and causes all member ports to leave the aggregation group.

Configuring a Layer 2 aggregation group

Configuring a Layer 2 static aggregation group

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Create a Layer 2 aggregate interface and enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number [ pex ]	When you create a Layer 2 aggregate interface, the system automatically creates a Layer 2 static aggregation group numbered the same. To create a Layer 2 extended-link aggregate interface, specify the pex keyword. You cannot specify the pex keyword when you create the Bridge-Aggregation 1 interface.
3. Exit to system view.	quit	N/A
4. Assign an interface to the specified Layer 2 aggregation group.	a Enter Layer 2 Ethernet interface view: interface interface-type interface-number b Assign the interface to the specified Layer 2 aggregation group: port link-aggregation group group-id [ force ]	Repeat these two substeps to assign more Layer 2 Ethernet interfaces to the aggregation group. To synchronize the attribute configurations and mac-vlan enable setting from the aggregate interface when the current interface joins the aggregation group, specify the force keyword.
5. (Optional.) Set the port priority for the interface.	link-aggregation port-priority priority	The default port priority of an interface is 32768.

Configuring a Layer 2 dynamic aggregation group

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the LACP system priority.	lacp system-priority priority	By default, the LACP system priority is 32768. Changing the LACP system priority might affect the aggregation states of the ports in a dynamic aggregation group.
3. Create a Layer 2 aggregate interface and enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number [ pex ]	When you create a Layer 2 aggregate interface, the system automatically creates a Layer 2 static aggregation group numbered the same. To create a Layer 2 extended-link aggregate interface, specify the pex keyword. You cannot specify the pex keyword when you create the Bridge-Aggregation 1 interface.
4. Configure the aggregation group to operate in dynamic mode.	link-aggregation mode dynamic	By default, an aggregation group operates in static mode.
5. Exit to system view.	quit	N/A
6. Assign an interface to a Layer 2 aggregation group or enable automatic assignment on that interface.	a Enter Layer 2 Ethernet interface view: interface interface-type interface-number b Assign the interface to a Layer 2 aggregation group or configure automatic assignment: port link-aggregation group { group-id [ force ] \| auto [ group-id ] }	Repeat these two substeps to assign more Layer 2 Ethernet interfaces to the aggregation group. To synchronize the attribute configurations and mac-vlan enable setting from the aggregate interface when the current interface joins the aggregation group, specify the force keyword. To enable automatic assignment, specify the auto keyword.
7. Set the LACP operating mode for the interface.	· Set the LACP operating mode to passive: lacp mode passive · Set the LACP operating mode to active: undo lacp mode	By default, LACP is operating in active mode.
8. Set the port priority for the interface.	link-aggregation port-priority priority	The default setting is 32768.
9. Set the short LACP timeout interval (3 seconds) for the interface.	lacp period short	By default, the long LACP timeout interval (90 seconds) is used by the interface. To avoid traffic interruption during an ISSU, do not set the short LACP timeout interval before performing the ISSU. For more information about ISSU, see Fundamentals Configuration Guide.

Configuring a Layer 3 aggregation group

Configuring a Layer 3 static aggregation group

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Create a Layer 3 aggregate interface and enter Layer 3 aggregate interface view.	interface route-aggregation interface-number	When you create a Layer 3 aggregate interface, the system automatically creates a Layer 3 static aggregation group numbered the same.
3. Exit to system view.	quit	N/A
4. Assign an interface to the specified Layer 3 aggregation group.	a Enter Layer 3 Ethernet interface view: interface interface-type interface-number b Assign the interface to the specified Layer 3 aggregation group: port link-aggregation group group-id	Repeat these two substeps to assign more Layer 3 Ethernet interfaces to the aggregation group.
5. (Optional.) Set the port priority for the interface.	link-aggregation port-priority priority	The default port priority of an interface is 32768.

Configuring a Layer 3 dynamic aggregation group

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the LACP system priority.	lacp system-priority priority	By default, the LACP system priority is 32768. Changing the LACP system priority might affect the aggregation states of the ports in the dynamic aggregation group.
3. Create a Layer 3 aggregate interface and enter Layer 3 aggregate interface view.	interface route-aggregation interface-number	When you create a Layer 3 aggregate interface, the system automatically creates a Layer 3 static aggregation group numbered the same.
4. Configure the aggregation group to operate in dynamic mode.	link-aggregation mode dynamic	By default, an aggregation group operates in static mode.
5. Exit to system view.	quit	N/A
6. Assign an interface to a Layer 3 aggregation group or enable automatic assignment on that interface.	a Enter Layer 3 Ethernet interface view: interface interface-type interface-number b Assign the interface to a Layer 3 aggregation group or configure automatic assignment: port link-aggregation group { group-id \| auto [ group-id ] }	Repeat these two substeps to assign more Layer 3 Ethernet interfaces to the aggregation group. To enable automatic assignment, specify the auto keyword.
7. Set the LACP operating mode for the interface.	· Set the LACP operating mode to passive: lacp mode passive · Set the LACP operating mode to active: undo lacp mode	By default, LACP is operating in active mode.
8. Set the port priority for the interface.	link-aggregation port-priority priority	The default setting is 32768.
9. Set the short LACP timeout interval (3 seconds) for the interface.	lacp period short	By default, the long LACP timeout interval (90 seconds) is used by the interface. To avoid traffic interruption during an ISSU, do not set the short LACP timeout interval before performing the ISSU. For more information about ISSU, see Fundamentals Configuration Guide.

Configuring automatic link aggregation

Overview

On a SmartMC network, you can use automatic link aggregation to aggregate the redundant physical links between devices to ease management and increase bandwidth and availability. For more information about SmartMC, see Network Management and Monitoring Configuration Guide.

Configuration restrictions and guidelines

On an interface, the port link-aggregation group setting takes precedence over automatic link aggregation. The interface will not be added to the aggregation group of an automatically created aggregate interface if it has been the member port of a manually created aggregate interface.

When automatic link aggregation is enabled, subinterface creation might fail on LLDP-enabled Layer 3 Ethernet interfaces.

As a best practice to ensure correct operation of dynamic aggregation groups, do not use automatic link aggregation and automatic member port assignment together.

Configuration prerequisites

Before you configure automatic link aggregation, enable LLDP on the peer devices.

Configuration procedure

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enable automatic link aggregation.	link-aggregation auto-aggregation enable	By default, automatic link aggregation is disabled.

Configuring S-MLAG

Configuration restrictions and guidelines

S-MLAG is intended for a non-IRF environment. Do not configure it on an IRF fabric. For more formation about IRF, see Virtual Technologies Configuration Guide.

An S-MLAG group can contain only one aggregate interface on each device.

The aggregate interfaces in an S-MLAG group cannot be used as DR interfaces or IPPs in DRNI. For more information about DR interfaces and IPPs, see DRNI configuration in Layer 2—LAN Switching Configuration Guide.

Do not configure the following settings on S-MLAG devices:

· LACP MAD.

· Maximum or minimum number of Selected ports.

· Automatic member port assignment.

· Ignoring port speed in setting the aggregation states of member ports.

As a best practice, maintain consistency across S-MLAG devices in service feature configuration.

Configuration prerequisites

Configure the link aggregation settings other than S-MLAG settings on each S-MLAG device. Make sure the settings are consistent across the S-MLAG devices.

Configuration procedure

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the LACP system MAC address.	lacp system-mac mac-address	By default, the LACP system MAC address is the bridge MAC address of the device. All S-MLAG devices must use the same LACP system MAC address.
3. Set the LACP system priority.	lacp system-priority priority	By default, the LACP system priority is 32768. All S-MLAG devices must use the same LACP system priority.
4. Set the LACP system number.	lacp system-number number	By default, the LACP system number is not set. You must assign a unique LACP system number to each S-MLAG device.
5. Enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number	N/A
6. Set the link aggregation mode to dynamic.	link-aggregation mode dynamic	By default, an aggregation group operates in static mode.
7. Assign the aggregate interface to an S-MLAG group.	port s-mlag group group-id	By default, an aggregate interface is not assigned to any S-MLAG group.

Configuring an aggregate interface

Most configurations that can be made on Layer 2 or Layer 3 Ethernet interfaces can also be made on Layer 2 or Layer 3 aggregate interfaces.

Configuring the description of an aggregate interface

You can configure the description of an aggregate interface for administration purposes, for example, describing the purpose of the interface.

To configure the description of an aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface or subinterface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	N/A
3. Configure the description of the aggregate interface or subinterface.	description text	By default, the description of an interface is interface-name Interface.

Configuring a dynamic aggregation group to use port speed as the prioritized criterion for reference port selection

CAUTION:

· Changing reference port selection criteria might cause transient traffic interruption. Make sure you understand the impact of this task on your network.

· You must perform this task at both ends of the aggregate link so the peer aggregation systems use the same criteria for reference port selection.

Perform this task to ensure that a dynamic aggregation group selects a high-speed member port as the reference port. After you perform this task, the priority order of criteria for reference port selection is device ID > port speed > port ID.

To configure a dynamic aggregation group to use port speed as the prioritized criterion for reference port selection:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	N/A
3. Shut down the interface.	shutdown	Changing reference port selection criteria might cause transient traffic interruption. As a best practice, shut down the aggregate interface before you make a change.
4. Specify port speed as the prioritized criterion for reference port selection.	lacp select speed	By default, port ID is the prioritized criterion for reference port selection of a dynamic aggregation group.
5. Bring up the interface.	undo shutdown	N/A

Specifying ignored VLANs for a Layer 2 aggregate interface

This feature takes effect only when the link type of a Layer 2 aggregate interface is hybrid or trunk.

By default, you cannot add a port to a Layer 2 link aggregation group if it has a different VLAN permit state or tagging mode than the aggregate interface.

To have a port participate in a Layer 2 aggregation despite its difference with the aggregate interface in the settings of a VLAN, configure that VLAN as an ignored VLAN.

To specify ignored VLANs for a Layer 2 aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number	N/A
3. Specify ignored VLANs.	link-aggregation ignore vlan vlan-id-list	By default, a Layer 2 aggregate interface does not ignore any VLANs.

Setting the MTU for a Layer 3 aggregate interface

The MTU of an interface affects IP packets fragmentation and reassembly on the interface.

To set the MTU for a Layer 3 aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter Layer 3 aggregate interface or subinterface view.	interface route-aggregation { interface-number \| interface-number.subnumber }	N/A
3. Set the MTU for the Layer 3 aggregate interface or subinterface.	mtu size	The default setting is 1500 bytes.

Setting the minimum and maximum numbers of Selected ports for an aggregation group

Overview

The bandwidth of an aggregate link increases as the number of Selected member ports increases. To avoid congestion, you can set the minimum number of Selected ports required for bringing up an aggregate interface.

This minimum threshold setting affects the aggregation states of aggregation member ports and the state of the aggregate interface.

· When the number of member ports eligible to be Selected ports is smaller than the minimum threshold, the following events occur:

¡ The eligible member ports are placed in Unselected state.

¡ The link layer state of the aggregate interface becomes down.

· When the number of member ports eligible to be Selected ports reaches or exceeds the minimum threshold, the following events occur:

¡ The eligible member ports are placed in Selected state.

¡ The link layer state of the aggregate interface becomes up.

The maximum number of Selected ports allowed in an aggregation group is limited by either manual configuration or hardware limitation, whichever value is smaller.

You can implement backup between two ports by performing the following tasks:

· Assigning two ports to an aggregation group.

· Setting the maximum number of Selected ports to 1 for the aggregation group.

Then, only one Selected port is allowed in the aggregation group, and the Unselected port acts as a backup port.

Configuration restrictions and guidelines

The minimum and maximum numbers of Selected ports must be the same for the local and peer aggregation groups.

For an aggregation group, the maximum number of Selected ports must be equal to or higher than the minimum number of Selected ports.

Configuration procedure

To set the minimum and maximum numbers of Selected ports for an aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	N/A
3. Set the minimum number of Selected ports for the aggregation group.	link-aggregation selected-port minimum min-number	By default, the minimum number of Selected ports is not specified for an aggregation group.
4. Set the maximum number of Selected ports for the aggregation group.	link-aggregation selected-port maximum max-number	By default, the maximum number of Selected ports for an aggregation group depends on hardware limitation.

Setting the expected bandwidth for an aggregate interface

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	N/A
3. Set the expected bandwidth for the interface.	bandwidth bandwidth-value	By default, the expected bandwidth (in kbps) is the interface baud rate divided by 1000.

Configuring an edge aggregate interface

This configuration takes effect only on aggregate interfaces in dynamic mode.

To configure an edge aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	N/A
3. Configure the aggregate interface as an edge aggregate interface.	lacp edge-port	By default, an aggregate interface does not operate as an edge aggregate interface.

Shutting down an aggregate interface

Shutting down or bringing up an aggregate interface affects the aggregation states and link states of member ports in the corresponding aggregation group as follows:

· When an aggregate interface is shut down, all Selected ports in the corresponding aggregation group become Unselected ports and all member ports go down.

· When an aggregate interface is brought up, the aggregation states of member ports in the corresponding aggregation group are recalculated.

To shut down an aggregate interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }	N/A
3. Shut down the aggregate interface or subinterface.	shutdown	By default, an aggregate interface or subinterface is up.

Restoring the default settings for an aggregate interface

You can restore all configurations on an aggregate interface to the default settings.

To restore the default settings for an aggregate interface:

Step	Command
1. Enter system view.	system-view
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface or subinterface view: interface route-aggregation { interface-number \| interface-number.subnumber }
3. Restore the default settings for the aggregate interface.	default

Disabling the default action of selecting a Selected port for dynamic aggregation groups that have not received LACPDUs

The default port selection action applies to dynamic aggregation groups.

This action automatically chooses the port with the lowest ID from among all up member ports as a Selected port if none of them has received LACPDUs before the LACP timeout interval expires.

After this action is disabled, a dynamic aggregation group will not have any Selected ports to forward traffic if it has not received LACPDUs before the LACP timeout interval expires.

To disable the default port selection action:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Disable the default port selection action.	lacp default-selected-port disable	By default, the default port selection action is enabled for dynamic aggregation groups.

Configuring load sharing for link aggregation groups

Setting load sharing modes for link aggregation groups

You can set the global or group-specific load sharing mode. A link aggregation group preferentially uses the group-specific load sharing mode. If the group-specific load sharing mode is not available, the group uses the global load sharing mode.

The load sharing modes take effect only on known unicast traffic.

Setting the global link-aggregation load sharing mode

In system view, the switch supports the following load sharing modes:

· Source IP address.

· Destination IP address.

· Source MAC address.

· Destination MAC address.

· Source IP address and destination IP address.

· Source IP address and source port.

· Destination IP address and destination port.

· Source IP address, source port, destination IP address, and destination port.

· Any combination of ingress port, source MAC address, and destination MAC address.

To set the global link-aggregation load sharing mode:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Set the global link-aggregation load sharing mode.	link-aggregation global load-sharing mode { destination-ip \| destination-mac \| destination-port \| ingress-port \| source-ip \| source-mac \| source-port } *	By default, the device distributes traffic automatically based on packet types. · Layer 2 frames are load shared based on the Ethernet type, source and destination MAC addresses, and source port number. · IP packets are load shared based on the following information: ¡ Source and destination IP addresses. ¡ Source and destination port numbers. ¡ IP protocol number. · MPLS packets are load shared based on Layer 1 and Layer 2 MPLS labels, and source and destination IP addresses. · MPLS L2VPN packets terminated on the device are load shared based on source and destination MAC addresses. · MPLS L3VPN packets terminated on the device are load shared based on source and destination IP addresses.

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Set the global link-aggregation load sharing mode.

link-aggregation global load-sharing mode { destination-ip | destination-mac | destination-port | ingress-port | source-ip | source-mac | source-port } *

By default, the device distributes traffic automatically based on packet types.

· Layer 2 frames are load shared based on the Ethernet type, source and destination MAC addresses, and source port number.

· IP packets are load shared based on the following information:

¡ Source and destination IP addresses.

¡ Source and destination port numbers.

¡ IP protocol number.

· MPLS packets are load shared based on Layer 1 and Layer 2 MPLS labels, and source and destination IP addresses.

· MPLS L2VPN packets terminated on the device are load shared based on source and destination MAC addresses.

· MPLS L3VPN packets terminated on the device are load shared based on source and destination IP addresses.

Setting the group-specific load sharing mode

In Layer 2 aggregate interface view, the switch supports the following per-flow load sharing modes:

· Source IP address.

· Destination IP address.

· Source MAC address.

· Destination MAC address.

· Layer 1 MPLS label.

· Destination IP address and source IP address.

· Destination MAC address and source MAC address.

· Layer 1 MPLS label and Layer 2 MPLS label.

To set the load sharing mode for an aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter Layer 2 aggregate interface view.	interface bridge-aggregation interface-number	N/A
3. Set the load sharing mode for the aggregation group.	link-aggregation load-sharing mode { { destination-ip \| destination-mac \| mpls-label1 \| mpls-label2 \| source-ip \| source-mac } * \| flexible }	By default, the load sharing mode is the same as the global load sharing mode.

Enabling local-first load sharing for link aggregation

Overview

Use local-first load sharing in a multichassis link aggregation scenario to distribute traffic preferentially across member ports on the ingress card or device.

When you aggregate ports on different member devices in an IRF fabric, you can use local-first load sharing to reduce traffic on IRF links, as shown in Figure 6. For more information about IRF, see Virtual Technologies Configuration Guide.

NOTE:

This feature takes effect only on known unicast traffic.

Figure 6 Load sharing for multichassis link aggregation in an IRF fabric

Configuration restrictions and guidelines

This feature is available only in IRF mode.

To perform local-first load sharing on an aggregation, you must configure local-first load sharing both globally and on the aggregate interface.

Configuration procedure

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enable local-first load sharing for link aggregation globally.	link-aggregation load-sharing mode local-first	By default, local-first load sharing is globally enabled for link aggregation.
3. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	N/A
4. Enable local-first load sharing on the aggregate interface.	link-aggregation group load-sharing mode local-first	By default, local-first load sharing is not configured on aggregate interfaces.

Enabling BFD for an aggregation group

BFD for Ethernet link aggregation can monitor member link status in an aggregation group. After you enable BFD on an aggregate interface, each Selected port in the aggregation group establishes a BFD session with its peer port. BFD operates differently depending on the aggregation mode.

· BFD for static aggregation—When BFD detects a link failure, BFD notifies the Ethernet link aggregation module that the peer port is unreachable. The local port is placed in Unselected state. The BFD session between the local and peer ports remains, and the local port keeps sending BFD packets. When BFD on the local port receives packets from the peer port upon link recovery, BFD notifies the Ethernet link aggregation module that the peer port is reachable. Then, the local port is placed in Selected state again. This mechanism ensures that the local and peer ports of a static aggregate link have the same aggregation state.

· BFD for dynamic aggregation—When BFD detects a link failure, BFD notifies the Ethernet link aggregation module that the peer port is unreachable. BFD clears the session and stops sending BFD packets. When the local port is placed in Selected state again upon link recovery, the local port establishes a new session with the peer port and BFD notifies the Ethernet link aggregation module that the peer port is reachable. Because BFD provides fast failure detection, the local and peer systems of a dynamic aggregate link can negotiate the aggregation state of their member ports faster.

For more information about BFD, see High Availability Configuration Guide.

Configuration restrictions and guidelines

When you enable BFD for an aggregation group, follow these restrictions and guidelines:

· Make sure the source and destination IP addresses are reversed between the two ends of an aggregate link. For example, if you execute link-aggregation bfd ipv4 source 1.1.1.1 destination 2.2.2.2 at the local end, execute link-aggregation bfd ipv4 source 2.2.2.2 destination 1.1.1.1 at the peer end. The source and destination IP addresses cannot be the same.

· The BFD parameters configured on an aggregate interface take effect on all BFD sessions in the aggregation group. BFD sessions for link aggregation do not support the echo packet mode or the Demand mode.

· As a best practice, do not configure a protocol to collaborate with BFD on a BFD-enabled aggregate interface.

· Make sure the number of member ports in a BFD-enabled aggregation group is less than or identical to the number of BFD sessions supported by the device. If the aggregation group contains more member ports than the supported sessions, some Selected ports might change to the Unselected state.

· If the number of BFD sessions differs between the two ends of an aggregate link, check their settings for inconsistency in the maximum number of Selected ports. You must make sure the two ends have the same setting for the maximum number of Selected ports.

Configuration procedure

To enable BFD for an aggregation group:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter aggregate interface view.	· Enter Layer 2 aggregate interface view: interface bridge-aggregation interface-number · Enter Layer 3 aggregate interface view: interface route-aggregation interface-number	N/A
3. Enable BFD for the aggregation group.	link-aggregation bfd ipv4 source ip-address destination ip-address	By default, BFD is disabled for an aggregation group.

Displaying and maintaining Ethernet link aggregation

Execute display commands in any view and reset commands in user view.

Task	Command
Display information for an aggregate interface or multiple aggregate interfaces.	display interface [ { bridge-aggregation \| route-aggregation } [ interface-number ] ] [ brief [ description \| down ] ]
Display the local system ID.	display lacp system-id
Display the global or group-specific link-aggregation load sharing modes.	display link-aggregation load-sharing mode [ interface [ { bridge-aggregation \| route-aggregation } interface-number ] ]
Display detailed link aggregation information for link aggregation member ports.	display link-aggregation member-port [ interface-list \| auto ]
Display summary information about all aggregation groups.	display link-aggregation summary
Display detailed information about the specified aggregation groups.	display link-aggregation verbose [ { bridge-aggregation \| route-aggregation } [ interface-number ] ]
Clear LACP statistics for the specified link aggregation member ports.	reset lacp statistics [ interface interface-list ]
Clear statistics for the specified aggregate interfaces.	reset counters interface [ { bridge-aggregation \| route-aggregation } [ interface-number ] ]

Ethernet link aggregation configuration examples

Layer 2 static aggregation configuration example

Network requirements

On the network shown in Figure 7, perform the following tasks:

· Configure a Layer 2 static aggregation group on both Device A and Device B.

· Enable VLAN 10 at one end of the aggregate link to communicate with VLAN 10 at the other end.

· Enable VLAN 20 at one end of the aggregate link to communicate with VLAN 20 at the other end.

Figure 7 Network diagram

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Configuration procedure

1. Configure Device A:

# Create VLAN 10, and assign port GigabitEthernet 1/0/4 to VLAN 10.

<DeviceA> system-view

[DeviceA] vlan 10

[DeviceA-vlan10] port gigabitethernet 1/0/4

[DeviceA-vlan10] quit

# Create VLAN 20, and assign port GigabitEthernet 1/0/5 to VLAN 20.

[DeviceA] vlan 20

[DeviceA-vlan20] port gigabitethernet 1/0/5

[DeviceA-vlan20] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 1.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] quit

# Assign ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to link aggregation group 1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/2] quit

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/3] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as a trunk port and assign it to VLANs 10 and 20.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] port link-type trunk

[DeviceA-Bridge-Aggregation1] port trunk permit vlan 10 20

[DeviceA-Bridge-Aggregation1] quit

2. Configure Device B in the same way Device A is configured. (Details not shown.)

Verifying the configuration

# Display detailed information about all aggregation groups on Device A.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Bridge-Aggregation1

Aggregation Mode: Static

Loadsharing Type: Shar

Management VLANs: None

Port Status Priority Oper-Key

GE1/0/1(R) S 32768 1

GE1/0/2 S 32768 1

GE1/0/3 S 32768 1

The output shows that link aggregation group 1 is a Layer 2 static aggregation group that contains three Selected ports.

Layer 2 dynamic aggregation configuration example

Network requirements

On the network shown in Figure 8, perform the following tasks:

· Configure a Layer 2 dynamic aggregation group on both Device A and Device B.

· Enable VLAN 10 at one end of the aggregate link to communicate with VLAN 10 at the other end.

· Enable VLAN 20 at one end of the aggregate link to communicate with VLAN 20 at the other end.

Figure 8 Network diagram

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Configuration procedure

1. Configure Device A:

# Create VLAN 10, and assign the port GigabitEthernet 1/0/4 to VLAN 10.

<DeviceA> system-view

[DeviceA] vlan 10

[DeviceA-vlan10] port gigabitethernet 1/0/4

[DeviceA-vlan10] quit

# Create VLAN 20, and assign the port GigabitEthernet 1/0/5 to VLAN 20.

[DeviceA] vlan 20

[DeviceA-vlan20] port gigabitethernet 1/0/5

[DeviceA-vlan20] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 1, and set the link aggregation mode to dynamic.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] link-aggregation mode dynamic

[DeviceA-Bridge-Aggregation1] quit

# Assign ports GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to link aggregation group 1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/2] quit

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/3] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as a trunk port and assign it to VLANs 10 and 20.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] port link-type trunk

[DeviceA-Bridge-Aggregation1] port trunk permit vlan 10 20

[DeviceA-Bridge-Aggregation1] quit

2. Configure Device B in the same way Device A is configured. (Details not shown.)

Verifying the configuration

# Display detailed information about all aggregation groups on Device A.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Bridge-Aggregation1

Creation Mode: Manual

Aggregation Mode: Dynamic

Loadsharing Type: Shar

Management VLANs: None

System ID: 0x8000, 000f-e267-6c6a

Local:

Port Status Priority Index Oper-Key Flag

GE1/0/1(R) S 32768 11 1 {ACDEF}

GE1/0/2 S 32768 12 1 {ACDEF}

GE1/0/3 S 32768 13 1 {ACDEF}

Remote:

Actor Priority Index Oper-Key SystemID Flag

GE1/0/1 32768 81 1 0x8000, 000f-e267-57ad {ACDEF}

GE1/0/2 32768 82 1 0x8000, 000f-e267-57ad {ACDEF}

GE1/0/3 32768 83 1 0x8000, 000f-e267-57ad {ACDEF}

The output shows that link aggregation group 1 is a Layer 2 dynamic aggregation group that contains three Selected ports.

Layer 2 aggregation load sharing configuration example

Network requirements

On the network shown in Figure 9, perform the following tasks:

· Configure Layer 2 static aggregation groups 1 and 2 on Device A and Device B, respectively.

· Enable VLAN 10 at one end of the aggregate link to communicate with VLAN 10 at the other end.

· Enable VLAN 20 at one end of the aggregate link to communicate with VLAN 20 at the other end.

· Configure link aggregation groups 1 and 2 to load share traffic across aggregation group member ports.

¡ Configure link aggregation group 1 to load share packets based on source MAC addresses.

¡ Configure link aggregation group 2 to load share packets based on destination MAC addresses.

Figure 9 Network diagram

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Configuration procedure

1. Configure Device A:

# Create VLAN 10, and assign the port GigabitEthernet 1/0/5 to VLAN 10.

<DeviceA> system-view

[DeviceA] vlan 10

[DeviceA-vlan10] port gigabitethernet 1/0/5

[DeviceA-vlan10] quit

# Create VLAN 20, and assign the port GigabitEthernet 1/0/6 to VLAN 20.

[DeviceA] vlan 20

[DeviceA-vlan20] port gigabitethernet 1/0/6

[DeviceA-vlan20] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 1.

[DeviceA] interface bridge-aggregation 1

# Configure Layer 2 aggregation group 1 to load share packets based on source MAC addresses.

[DeviceA-Bridge-Aggregation1] link-aggregation load-sharing mode source-mac

[DeviceA-Bridge-Aggregation1] quit

# Assign ports GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 to link aggregation group 1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/2] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as a trunk port and assign it to VLAN 10.

[DeviceA] interface bridge-aggregation 1

[DeviceA-Bridge-Aggregation1] port link-type trunk

[DeviceA-Bridge-Aggregation1] port trunk permit vlan 10

[DeviceA-Bridge-Aggregation1] quit

# Create Layer 2 aggregate interface Bridge-Aggregation 2.

[DeviceA] interface bridge-aggregation 2

# Configure Layer 2 aggregation group 2 to load share packets based on destination MAC addresses.

[DeviceA-Bridge-Aggregation2] link-aggregation load-sharing mode destination-mac

[DeviceA-Bridge-Aggregation2] quit

# Assign ports GigabitEthernet 1/0/3 and GigabitEthernet 1/0/4 to link aggregation group 2.

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 2

[DeviceA-GigabitEthernet1/0/3] quit

[DeviceA] interface gigabitethernet 1/0/4

[DeviceA-GigabitEthernet1/0/4] port link-aggregation group 2

[DeviceA-GigabitEthernet1/0/4] quit

# Configure Layer 2 aggregate interface Bridge-Aggregation 2 as a trunk port and assign it to VLAN 20.

[DeviceA] interface bridge-aggregation 2

[DeviceA-Bridge-Aggregation2] port link-type trunk

[DeviceA-Bridge-Aggregation2] port trunk permit vlan 20

[DeviceA-Bridge-Aggregation2] quit

2. Configure Device B in the same way Device A is configured. (Details not shown.)

Verifying the configuration

# Display detailed information about all aggregation groups on Device A.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Bridge-Aggregation1

Aggregation Mode: Static

Loadsharing Type: Shar

Management VLANs: None

Port Status Priority Oper-Key

GE1/0/1(R) S 32768 1

GE1/0/2 S 32768 1

Aggregate Interface: Bridge-Aggregation2

Aggregation Mode: Static

Loadsharing Type: Shar

Management VLANs: None

Port Status Priority Oper-Key

GE1/0/3(R) S 32768 2

GE1/0/4 S 32768 2

The output shows that:

· Link aggregation groups 1 and 2 are both load-shared Layer 2 static aggregation groups.

· Each aggregation group contains two Selected ports.

# Display all the group-specific load sharing modes on Device A.

[DeviceA] display link-aggregation load-sharing mode interface

Bridge-Aggregation1 Load-Sharing Mode:

source-mac address

Bridge-Aggregation2 Load-Sharing Mode:

destination-mac address

The output shows that:

· Link aggregation group 1 distributes packets based on source MAC addresses.

· Link aggregation group 2 distributes packets based on destination MAC addresses.

Layer 2 edge aggregate interface configuration example

Network requirements

As shown in Figure 10, a Layer 2 dynamic aggregation group is configured on the device. The server is not configured with dynamic link aggregation.

Configure an edge aggregate interface so that both GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 can forward traffic to improve link reliability.

Figure 10 Network diagram

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Configuration procedure

# Create Layer 2 aggregate interface Bridge-Aggregation 1, and set the link aggregation mode to dynamic.

<Device> system-view

[Device] interface bridge-aggregation 1

[Device-Bridge-Aggregation1] link-aggregation mode dynamic

# Configure Layer 2 aggregate interface Bridge-Aggregation 1 as an edge aggregate interface.

[Device-Bridge-Aggregation1] lacp edge-port

[Device-Bridge-Aggregation1] quit

# Assign ports GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 to link aggregation group 1.

[Device] interface gigabitethernet 1/0/1

[Device-GigabitEthernet1/0/1] port link-aggregation group 1

[Device-GigabitEthernet1/0/1] quit

[Device] interface gigabitethernet 1/0/2

[Device-GigabitEthernet1/0/2] port link-aggregation group 1

[Device-GigabitEthernet1/0/2] quit

Verifying the configuration

# Display detailed information about all aggregation groups on the device when the server is not configured with dynamic link aggregation.

[Device] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Bridge-Aggregation1

Creation Mode: Manual

Aggregation Mode: Dynamic

Loadsharing Type: Shar

Management VLANs: None

System ID: 0x8000, 000f-e267-6c6a

Local:

Port Status Priority Index Oper-Key Flag

GE1/0/1 I 32768 11 1 {AG}

GE1/0/2 I 32768 12 1 {AG}

Remote:

Actor Priority Index Oper-Key SystemID Flag

GE1/0/1 32768 81 0 0x8000, 0000-0000-0000 {DEF}

GE1/0/2 32768 82 0 0x8000, 0000-0000-0000 {DEF}

The output shows that GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 are in Individual state when they do not receive LACPDUs from the server. Both GigabitEthernet 1/0/1 and GigabitEthernet 1/0/2 can forward traffic. When one port fails, its traffic is automatically switched to the other port.

Layer 3 static aggregation configuration example

Network requirements

On the network shown in Figure 11, perform the following tasks:

· Configure a Layer 3 static aggregation group on both Device A and Device B.

· Configure IP addresses and subnet masks for the corresponding Layer 3 aggregate interfaces.

Figure 11 Network diagram

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Configuration procedure

1. Configure Device A:

# Create Layer 3 aggregate interface Route-Aggregation 1, and configure an IP address and subnet mask for the aggregate interface.

<DeviceA> system-view

[DeviceA] interface route-aggregation 1

[DeviceA-Route-Aggregation1] ip address 192.168.1.1 24

[DeviceA-Route-Aggregation1] quit

# Assign Layer 3 Ethernet interfaces GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to aggregation group 1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/2] quit

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/3] quit

2. Configure Device B in the same way Device A is configured. (Details not shown.)

Verifying the configuration

# Display detailed information about all aggregation groups on Device A.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Route-Aggregation1

Aggregation Mode: Static

Loadsharing Type: Shar

Management VLANs: None

Port Status Priority Oper-Key

GE1/0/1(R) S 32768 1

GE1/0/2 S 32768 1

GE1/0/3 S 32768 1

The output shows that link aggregation group 1 is a Layer 3 static aggregation group that contains three Selected ports.

Layer 3 dynamic aggregation configuration example

Network requirements

On the network shown in Figure 12, perform the following tasks:

· Configure a Layer 3 dynamic aggregation group on both Device A and Device B.

· Configure IP addresses and subnet masks for the corresponding Layer 3 aggregate interfaces.

Figure 12 Network diagram

‌

Configuration procedure

1. Configure Device A:

# Create Layer 3 aggregate interface Route-Aggregation 1.

<DeviceA> system-view

[DeviceA] interface route-aggregation 1

# Set the link aggregation mode to dynamic.

[DeviceA-Route-Aggregation1] link-aggregation mode dynamic

# Configure an IP address and subnet mask for Route-Aggregation 1.

[DeviceA-Route-Aggregation1] ip address 192.168.1.1 24

[DeviceA-Route-Aggregation1] quit

# Assign Layer 3 Ethernet interfaces GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to aggregation group 1.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/2] quit

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 1

[DeviceA-GigabitEthernet1/0/3] quit

2. Configure Device B in the same way Device A is configured. (Details not shown.)

Verifying the configuration

# Display detailed information about all aggregation groups on Device A.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Route-Aggregation1

Creation Mode: Manual

Aggregation Mode: Dynamic

Loadsharing Type: Shar

Management VLANs: None

System ID: 0x8000, 000f-e267-6c6a

Local:

Port Status Priority Index Oper-Key Flag

GE1/0/1(R) S 32768 11 1 {ACDEF}

GE1/0/2 S 32768 12 1 {ACDEF}

GE1/0/3 S 32768 13 1 {ACDEF}

Remote:

Actor Priority Index Oper-Key SystemID Flag

GE1/0/1 32768 81 1 0x8000, 000f-e267-57ad {ACDEF}

GE1/0/2 32768 82 1 0x8000, 000f-e267-57ad {ACDEF}

GE1/0/3 32768 83 1 0x8000, 000f-e267-57ad {ACDEF}

The output shows that link aggregation group 1 is a Layer 3 dynamic aggregation group that contains three Selected ports.

S-MLAG configuration example

Network requirements

As shown in Figure 13, configure Device B, Device C, and Device D as S-MLAG devices to establish a multichassis aggregate link with Device A.

Figure 13 Network diagram

‌

Configuration procedure

1. Configure Device A:

# Create Layer 2 aggregate interface Bridge-Aggregation 10, and set the link aggregation mode to dynamic.

<DeviceA> system-view

[DeviceA] interface bridge-aggregation 10

[DeviceA-Bridge-Aggregation10] link-aggregation mode dynamic

[DeviceA-Bridge-Aggregation10] quit

# Assign GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 to aggregation group 10.

[DeviceA] interface gigabitethernet 1/0/1

[DeviceA-GigabitEthernet1/0/1] port link-aggregation group 10

[DeviceA-GigabitEthernet1/0/1] quit

[DeviceA] interface gigabitethernet 1/0/2

[DeviceA-GigabitEthernet1/0/2] port link-aggregation group 10

[DeviceA-GigabitEthernet1/0/2] quit

[DeviceA] interface gigabitethernet 1/0/3

[DeviceA-GigabitEthernet1/0/3] port link-aggregation group 10

[DeviceA-GigabitEthernet1/0/3] quit

2. Configure Device B:

# Set the LACP system MAC address to 0001-0001-0001.

<DeviceB> system-view

[DeviceB] lacp system-mac 1-1-1

# Set the LACP system priority to 123.

[DeviceB] lacp system-priority 123

# Set the LACP system number to 1.

[DeviceB] lacp system-number 1

# Create Layer 2 aggregate interface Bridge-Aggregation 2, and set the link aggregation mode to dynamic.

[DeviceB] interface bridge-aggregation 2

[DeviceB-Bridge-Aggregation2] link-aggregation mode dynamic

# Assign Bridge-Aggregation 2 to S-MLAG group 100.

[DeviceB-Bridge-Aggregation2] port s-mlag group 100

# Assign GigabitEthernet 1/0/1 to aggregation group 2.

[DeviceB] interface gigabitethernet 1/0/1

[DeviceB-GigabitEthernet1/0/1] port link-aggregation group 2

[DeviceB-GigabitEthernet1/0/1] quit

3. Configure Device C:

# Set the LACP system MAC address to 0001-0001-0001.

<DeviceC> system-view

[DeviceC] lacp system-mac 1-1-1

# Set the LACP system priority to 123.

[DeviceC] lacp system-priority 123

# Set the LACP system number to 2.

[DeviceC] lacp system-number 2

# Create Layer 2 aggregate interface Bridge-Aggregation 3, and set the link aggregation mode to dynamic.

[DeviceC] interface bridge-aggregation 3

[DeviceC-Bridge-Aggregation3] link-aggregation mode dynamic

# Assign Bridge-Aggregation 3 to S-MLAG group 100.

[DeviceC-Bridge-Aggregation3] port s-mlag group 100

# Assign GigabitEthernet 1/0/1 to aggregation group 3.

[DeviceC] interface gigabitethernet 1/0/1

[DeviceC-GigabitEthernet1/0/1] port link-aggregation group 3

[DeviceC-GigabitEthernet1/0/1] quit

4. Configure Device D:

# Set the LACP system MAC address to 0001-0001-0001.

<DeviceD> system-view

[DeviceD] lacp system-mac 1-1-1

# Set the LACP system priority to 123.

[DeviceD] lacp system-priority 123

# Set the LACP system number to 3.

[DeviceD] lacp system-number 3

# Create Layer 2 aggregate interface Bridge-Aggregation 4, and set the link aggregation mode to dynamic.

[DeviceD] interface bridge-aggregation 4

[DeviceD-Bridge-Aggregation4] link-aggregation mode dynamic

# Assign Bridge-Aggregation 4 to S-MLAG group 100.

[DeviceD-Bridge-Aggregation4] port s-mlag group 100

# Assign GigabitEthernet 1/0/1 to aggregation group 4.

[DeviceD] interface gigabitethernet 1/0/1

[DeviceD-GigabitEthernet1/0/1] port link-aggregation group 4

[DeviceD-GigabitEthernet1/0/1] quit

Verifying the configuration

# Verify that GigabitEthernet 1/0/1 through GigabitEthernet 1/0/3 on Device A are Selected ports.

[DeviceA] display link-aggregation verbose

Loadsharing Type: Shar -- Loadsharing, NonS -- Non-Loadsharing

Port Status: S -- Selected, U -- Unselected, I -- Individual

Port: A -- Auto port, M -- Management port, R -- Reference port

Flags: A -- LACP_Activity, B -- LACP_Timeout, C -- Aggregation,

D -- Synchronization, E -- Collecting, F -- Distributing,

G -- Defaulted, H -- Expired

Aggregate Interface: Bridge-Aggregation10

Creation Mode: Manual

Aggregation Mode: Dynamic

Loadsharing Type: Shar

Management VLANs: None

System ID: 0x8000, 40fa-264f-0100

Local:

Port Status Priority Index Oper-Key Flag

GE1/0/1(R) S 32768 1 1 {ACDEF}

GE1/0/2 S 32768 2 1 {ACDEF}

GE1/0/3 S 32768 3 1 {ACDEF}

Remote:

Actor Priority Index Oper-Key SystemID Flag

GE1/0/1 32768 16385 50100 0x7b , 0001-0001-0001 {ACDEF}

GE1/0/2 32768 32769 50100 0x7b , 0001-0001-0001 {ACDEF}

GE1/0/3 32768 49153 50100 0x7b , 0001-0001-0001 {ACDEF}

04-Layer 2 - LAN Switching Configuration Guide

Configuration types

Reference port selection process

Setting the aggregation state of each member port

LACP

LACP functions

LACP operating modes

LACP priorities

LACP timeout interval

Methods to assign interfaces to a dynamic link aggregation group

Automatic member interface assignment

Load sharing modes for link aggregation groups

Aggregation member interface restrictions

Configuration consistency requirements

Miscellaneous

Configuring a Layer 3 static aggregation group

Overview

Configuration restrictions and guidelines

Configuration prerequisites

Configuration procedure

Configuration restrictions and guidelines

Configuration prerequisites

Configuration procedure

Configuration restrictions and guidelines

Configuration procedure

Setting the expected bandwidth for an aggregate interface

Setting the global link-aggregation load sharing mode

Setting the group-specific load sharing mode

Overview

Configuration restrictions and guidelines

Configuration procedure

Configuration restrictions and guidelines

Configuration procedure

Network requirements

Configuration procedure

Verifying the configuration

Network requirements

Configuration procedure

Verifying the configuration

Network requirements

Configuration procedure

Verifying the configuration

Network requirements

Configuration procedure

Verifying the configuration

Network requirements

Configuration procedure

Verifying the configuration

Network requirements

Configuration procedure

Verifying the configuration

S-MLAG configuration example

Network requirements

Configuration procedure

Verifying the configuration

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