R3721-F3210-F3171-HP High-End Firewalls High Availability Configuration Guide-6PW101

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Configuring Ethernet link aggregation
Feature and hardware compatibility
Feature F1000-A-EI/S-EI F1000-E F5000 Firewall module
Limiting the number of Selected
ports for an aggregation group
No No Yes No
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.
As shown in Figure 60, D
evice A and Device B are connected by three physical Ethernet links. These
physical Ethernet links are combined into an aggregate link, Link Aggregation 1. The bandwidth of this
aggregate link is as high as the total bandwidth of these three physical Ethernet links. At the same time,
the three Ethernet links back up one another.
Figure 60 Ethernet link aggregation
Basic concepts
Aggregation group, member port, and aggregate interface
Link aggregation is implemented through link aggregation groups. An aggregation group is a group of
Ethernet interfaces combined 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.
Aggregate interfaces have the following types: 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 device 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.
Eth1/2
Eth1/1
Eth1/3
Link aggregation 1
Eth1/2
Eth1/1
Eth1/3
Device A Device B