HP VPN Firewall Appliances High Availability Configuration Guide

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Configuring Ethernet link aggregation
The device does not support the dynamic aggregation mode.
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 65, Device
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 the three physical Ethernet links. At the same time, the
three Ethernet links back up one another.
Figure 65 Ethernet link aggregation
Basic concepts
This section describes some basic link aggregation concepts.
Aggregation group, member port, and aggregate interface
Link aggregation is implemented by combining Ethernet interfaces into a link aggregation group. Each
link aggregation group has one logical aggregate interface. To an upper layer entity, a link aggregation
group appears to be a single logical link and data traffic is transmitted through the aggregate interface.
The rate of an aggregate interface equals the total rate of its member ports in Selected state, and its
duplex mode is the same as the selected member ports. For more information about the states of member
ports in an aggregation group, see "Aggregation states of member ports in an aggregation group."
Aggregate int
erfaces include the following types:
• Layer 2 aggregate interfaces—On a Layer 2 aggregate interface, you can create subinterfaces,
which are called Layer 2 aggregate subinterfaces. Layer 2 aggregate subinterfaces are logical
interfaces that operate at the data link layer and forward Ethernet frames across VLANs on a
firewall module (a subinterface of a VLAN forwards Ethernet frames to a subinterface of another
VLAN).
• Layer 3 aggregate interfaces—On a Layer 3 aggregate interface, you can create subinterfaces.
The Layer 3 aggregate subinterfaces are logical interfaces operating at the network layer. They can
receive VLAN tagged packets for their Layer 3 aggregate interface.