Westermo RedFox Series - Manual (Page 366)

Westermo OS Management Guide
Version 4.17.0-0
LACP relies upon periodic transmission of information and state between the
switches. The protocol messages (LACP-PDUs) are sent by the first party (the
Actor) to the second party (the Actor’s protocol Partner) with information about
what the Actor knows, both about its own state and that of the Partner.
Switches can be configured to active or passive participation in LACP. Passive
LACP indicates the preference for not transmitting LACP-PDUs unless its Partner
is Active LACP, i.e. it does not generate any LACP traffic by its own. Active LACP
indicates the preference to participate in the protocol regardless of the Partner
setting, i.e. it always generates LACP traffic.
LACP-PDUs are transmitted periodically when either the Actor or the Partner is
configured with Active LACP. These transmissions will occur at either a fast or slow
transmission rate depending upon the timeout setting (short or long timeout) of
the Partner system.
The LACP state is determined by the contents of the LACP-PDUs and can be in
any of the following states:
Detached The port is being detached from the aggregator.
Waiting The port is being attached to the aggregator.
Attached The port is attached to the selected aggregator.
Collecting Indicates that the receive function of this link is enabled.
Distributing Indicates that the transmit function of this link is enabled.
The switch will set a member port in forwarding state when LACP state is Dis-
tributing. For all other LACP states the port state will be blocking
3 . The aggregate
is in forwarding state as long as at least one member port is in forwarding state.
Also, the aggregate will be up as long as at least one member port is up.
WeOS assumes that the configured aggregate connects two switches. If the ag-
gregate member ports on one switch is connected to several other switches LACP
will only include member ports to one of the neighbours in the active port set:
❼ Ports to the neighbour with the highest total bandwidth will be selected.
❼ If several aggregates share the same bandwidth, then the aggregate is se-
lected based on LACP system priority, system identifier, port priority, and
operational key.
3 RSTP or FRNT are run over the aggregate, those protocols may also decide to set the ports in
blocking state.
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