H3C Technologies H3C SecPath F1000-E - Manual (Page 91)

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Link Aggregation Configuration
NOTE:
Only the SecPath F5000-A5 supports link aggregation.
Overview
Ethernet link aggregation, or simply link aggregation, combines multiple physical Ethernet ports into one
logical link, called an aggregate link. Link aggregation delivers the following benefits:
• Increases bandwidth beyond the limits of any single link. In an aggregate link, traffic is distributed
across the member ports.
• Improves link reliability. The member ports dynamically back up one another. When a member port
fails, its traffic is automatically switched to other member ports.
Basic Concepts
Aggregation group, member port, aggregate interface
Link aggregation is implemented through link aggregation groups. An aggregation group is a group of
Ethernet interfaces aggregated together, which are called member ports of the aggregation group. For
each aggregation group, a logical interface, called an aggregate interface is created. To an upper layer
entity that uses the link aggregation service, a link aggregation group looks like a single logical link and
data traffic is transmitted through the aggregate interface.
There are two types of aggregate interfaces: bridge-aggregation (BAGG) interfaces, also called Layer 2
aggregate interfaces, and route-aggregation (RAGG) interfaces, also called Layer 3 aggregate
interfaces. When you create an aggregate interface, the firewall automatically creates an aggregation
group of the same type and number as the aggregate interface. For example, when you create interface
Bridge-aggregation 1, Layer 2 aggregation group 1 is created.
You can assign Layer 2 Ethernet interfaces only to a Layer 2 aggregation group, and Layer 3 Ethernet
interfaces only to a Layer 3 aggregation group.
Aggregation states of member ports in an aggregation group
A member port in an aggregation group can be in either of the following two aggregation states:
• Selected: A Selected port can forward user traffic.
• Unselected: An Unselected port cannot forward user traffic.
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 member ports are assigned the same operational key.