Allied Telesis AT-S62 - Manual (Page 127)

AT-S62 Menus Interface User’s Guide
Section I: Basic Operations 127
LACP System Priority
It is possible for two devices interconnected by an aggregate trunk to
encounter a conflict when forming a trunk. For example, the two devices
might not support the same number of active ports in an aggregate
trunk or might not agree on which ports are to be active and which are
to be in standby.
If a conflict occurs, the devices need a mechanism for resolving the
problem, a means by which they can decide whose LACP settings are to
take precedence. That is the function of the system LACP priority value.
A hexadecimal value of from 1 to FFFF, this parameter is used whenever
the devices encounter a conflict creating a trunk. The lower the number,
the higher the priority. The settings on the device with the higher
priority takes precedence over the settings on the other device. If both
devices have the same system LACP priority value, the settings on the
switch with the lowest MAC address take precedence.
This parameter can prove useful when connecting an aggregate trunk
between an AT-8500 Series switch and another 802.3ad-compliant
device that does not have the same LACP trunking capabilities. If the
other device’s capability is less than that of the AT-8500 Series’, you
should give that device the higher priority so that its settings are used by
both devices when forming the trunk.
For example, an aggregate trunk of six links between an AT-8500 Series
switch and an 802.3ad-compliant device that supported up to four
active links at one time could possibly result in a conflict. The AT-8500
Series switch would try to use all six links as active, since it can handle up
to eight active links in a trunk at one time, while the other device would
want to use only four ports as active. By giving the other 802.3ad device
the higher priority, the conflict would be avoided because the AT-8500
Series switch would then use only four active links. The other ports
would be in standby mode.
Adminkey Parameter
The adminkey is a hexadecimal value from 1 to FFFF that identifies an
aggregator. Each aggregator on a switch must have a unique adminkey.
The adminkey is limited to a switch. Two aggregators on different
switches can have the same adminkey without creating a conflict.