R3166-R3206-HP High-End Firewalls High Availability Configuration Guide-6PW101

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NOTE:
• Class-two configurations made on an aggregate interface are automatically synchronized to all its
member ports. These configurations are retained on the member ports even after the aggregate
interface is removed.
• Any class-two configuration change may affect the aggregation state of link aggregation member ports
and thus ongoing traffic. To make sure that you are aware of the risk, the system displays a warning
message every time you attempt to change a class-two configuration setting on a member port.
• Class-one configurations, which are configurations that do not affect the aggregation state of the
member port even if they are different from those on the aggregate interface. GVRP and MSTP
settings are examples of class-one configurations.
Reference port
When setting the aggregation state of the ports in an aggregation group, the system automatically picks
a member port as the reference. This port is called the reference port of the aggregation group. The port
attribute and class-two configurations of every other member port are compared with those of the
reference port.
LACP protocol
The IEEE 802.3ad Link Aggregation Control Protocol (LACP) enables dynamic aggregation of physical
links. It uses link aggregation control protocol data units (LACPDUs) for exchanging aggregation
information between LACP-enabled devices.
1. LACP functions
Based on the fields carried in LACPDUs, the functions delivered by the IEEE 802.3ad LACP fall into basic
LACP functions and extended LACP functions, as described in Table 7.
Table 11 Basic and ext
ended LACP functions
Cate
g
or
y
Descri
p
tion
Basic LACP functions
Implemented through the basic LACPDU fields including the system LACP priority,
system MAC address, port aggregation priority, port number, and operational key.
Each member port in a LACP-enabled aggregation group exchanges the above
information with its peer. When a member port receives an LACPDU, it compares
the received information with the information received on the other member ports. In
this way the two systems reach an agreement on which ports should be placed in the
selected state.
Extended LACP
functions
Implemented by extending the LACPDU with new Type/Length/Value (TLV) fields.
This is how the LACP multi-active detection (MAD) mechanism of the Intelligent
Resilient Framework (IRF) feature is implemented.
• If a device supports both LACP extensions and IRF, it can participate in LACP
MAD either as an IRF member device or an intermediate device.
• If a device supports LACP extensions but not IRF, it can participate in LACP MAD
only as an intermediate device.
2. LACP priorities
There are two types of LACP priorities: system LACP priority and port aggregation priority, as described
in Table 8.