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

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Table 12 LACP priorities
T
yp
e Descri
p
tion Remarks
System LACP
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 system LACP
priority sets the Selected state of member ports on its side first and then
the system that has lower priority sets port state accordingly.
The smaller the
priority value,
the higher the
priority.
Port aggregation
priority
Determines the likelihood of a member port to be selected on a system.
The higher port aggregation priority, the higher likelihood.
3. 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 fails to receive LACPDUs from the peer within three times the
LACP timeout interval, the member port assumes that the peer port has failed. You can configure
the LACP timeout interval as the short timeout interval (1 second) or the long timeout interval (30
seconds).
Link aggregation modes
Link aggregation has the following modes: dynamic and static. Dynamic link aggregation uses LACP
and static link aggregation does not. Table 13 c
ompares the two aggregation modes.
Table 13 A comparison between static and dynamic aggregation modes
Aggregatio
n mode
LACP status on
member
p
orts
Pros Cons
Static Disabled
Aggregation is stable. The
aggregation state of the member
ports are not affected by the peer
ports.
The member ports do not adjust the
aggregation state according to
that of the peer ports. The
administrator must manually
maintain link aggregations.
Dynamic Enabled
The administrator does not need to
maintain link aggregations. The
peer systems maintain the
aggregation state of the member
ports automatically.
Aggregation is unstable. The
aggregation state of member ports
is susceptible to network changes.
In a dynamic link aggregation group:
• A Selected port can receive and send LACPDUs.
• An Unselected port can receive and send LACPDUs only if it is up and has the same class-two
configurations as the aggregate interface.
NOTE:
Dynamic aggregation is not supported.
Aggregating links in static mode
LACP is disabled on the member ports in a static aggregation group. You must manually maintain the
aggregation state of the member ports.