Nokia ESB26 User Manual page 62

7.
Passive: The switch does not initiate the LAG, but understands the LACP packet. The switch
will reply to the received LACP packet to eventually form the LAG if the other end (in active
state) requests it to do so.
Active: The switch is willing to form an aggregate link, and initiate the negotiation. The link
aggregate will be formed if the other end is running in LACP active or passive mode.
LACP Parameters
The following parameters are used in configuring LACP:
•
System priority - Each switch running LACP must have a system priority.
The system priority can be specified automatically or through the link-
aggregation lacp system-priority command in Protocol Configuration mode.
The switch uses the MAC address and the system priority to form the system
ID that is also used during negotiation with other systems.
• Port priority - Each port in the switch must have a port priority. The port
priority can be specified automatically or through the link-aggregation lacp
command in Interface configuration mode. The port priority and the port
number form the port identifier. The switch uses the port priority to decide
which ports to put in standby mode when a hardware limitation prevents all
compatible ports from aggregating.
When enabled, LACP always tries to configure the maximum number of compatible ports in a
LAG, up to the maximum allowed by the hardware. If LACP is unable to aggregate all the
ports that are compatible (for example, the remote system might have more restrictive
hardware limitations), then all the ports that cannot be actively included in the LAG are put in
hot standby state and are used only if one of the channeled ports fails.
Benefits
The goals and objectives of link aggregation are specified in the IEEE standard 802.3ad.
Among these, LACP provides:
• Rapid automatic configuration and reconfiguration
If physical connections are changed or fail, LACP automatically reconfigures
the connection, typically within a second or less.
• Deterministic behavior
The resulting aggregation can be determined by the capabilities of the individual
links and their physical connectivity, regardless of the order in which events
occur.
• Low risk of duplication or misorder
There is a high probability that the order of frames is maintained and that frames
are not duplicated, both in regular operation and during link reconfiguration.
LAG ID Numbers
LAG ID numbers are used to identify specific LAGs in configuration commands. LAG ID
numbers uniquely identify the group of ports that participate in the LAG. You can define up to
7 LAGs. The valid LAG ID numbers are 1÷7.
MN700004 Rev 01
Link Aggregation Groups (LAGs)
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