HP 3100 Series, Configuration Manual

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Category Description
Extended
LACP functions
Implemented by extending the LACPDU with new Type/Length/Value (TLV) fields.
2.
LACP priorities
LACP priorities have the following types: system LACP priority and port aggregation priority.
Table 4 LACP priorities
Type Description 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 the 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 the port aggregation priority, the higher the
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 either 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 5 compares the two aggregation modes.
Table 5 A comparison between static and dynamic aggregation modes
Aggregation
mode
LACP status
on member
ports
Pros Cons
Static Disabled
Aggregation is stable. Peers do
not affect the aggregation state of
the member 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 the member
ports is susceptible to network
changes.
The following points apply to 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.