HP HP 830 Series, Configuration Manual

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• Static aggregation limits the number of Selected ports in an aggregation group. When the number
of the candidate selected ports is under the limit, all the candidate selected ports become Selected
ports. When the limit is exceeded, set the candidate selected ports with smaller port numbers in
Selected state and those with greater port numbers in Unselected state.
•
If all the member ports are down, set their states to Unselected.
•
Set the ports that cannot aggregate with the reference port to the Unselected state, for example, as
a result of the inter-board aggregation restriction.
A port that joins the aggregation group after the limit on the number of Selected ports has been reached
will not be placed in Selected state even if it should be in normal cases. This can prevent the ongoing
traffic on the current Selected ports from being interrupted. You should avoid the situation however, as
this may cause the Selected/Unselected state of a port to change after a reboot.
Dynamic aggregation mode
LACP is enabled on member ports in a dynamic aggregation group.
In a dynamic aggregation group,
•
A Selected port can receive and transmit LACPDUs.
• An Unselected port can receive and send LACPDUs only if it is up and with the same configurations
as those on the aggregate interface.
In a dynamic aggregation group, the system sets the ports to Selected or Unselected state in the following
steps:
1. The local system (the actor) negotiates with the remote system (the partner) to determine the port
state based on the port IDs on the end with the preferred system ID. The following negotiation
procedure applies:
{
Compare the system ID (comprising the system LACP priority and the system MAC address) of
the actor with that of the partner. The system with the lower LACP priority wins. If they are the
same, compare the system MAC addresses. The system with the smaller MAC address wins.
{
Compare the port IDs of the ports on the system with the smaller system ID. A port ID comprises
a port LACP priority and a port number. First, compare the port LACP priorities. The port with the
lower LACP priority wins. If two ports are with the same LACP priority, compare their port
numbers. The port with the smaller port number is selected as the reference port.
{
If a port in up state is with the same port attributes and class-two configuration as the reference
port, and the peer port of the port is with the same port attributes and class-two configurations
as the peer port of the reference port, consider the port as a candidate selected port. Otherwise
set the port to the Unselected state.
{
The number of Selected ports that an aggregation group can contain is limited. When the
number of candidate selected ports is under the limit, all the candidate selected ports are set to
Selected state. When the limit is exceeded, the system selects the candidate selected ports with
smaller port IDs as the Selected ports, and set other candidate selected ports to Unselected state.
At the same time, the peer device, being aware of the changes, also changes the state of its
ports.
2. Set the ports that cannot aggregate with the reference port to the Unselected state, for example, as
the result of the inter-board aggregation restriction.
The following guidelines apply to static and dynamic aggregation modes:
• The maximum number of Selected ports allowed in an aggregation group depends on your device
model.