Dell PowerEdge M420, Reference Manual

Page: 573 / 1682

Port Channel Commands
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Port Channel Commands
Care must be taken while enabling this type of configuration. If the Partner
System is not 802.3AD compliant or the Link Aggregation Control protocol is
not enabled, there may be network instability. Network instability occurs
when one side assumes that the members in an aggregation are one single
link, while the other side is oblivious to this aggregation and continues to
treat the 'members' as individual links.
In the PowerConnect system, the Actor System waits for 3 seconds before
aggregating manually. The 3 second wait time is specified by the protocol
standard.
If a manual LAG member sees an LACPDU that contains information
different from the currently configured default partner values, that particular
member drops out of the LAG. This configured member does not aggregate
with the LAG until all the other active members see the new information.
When each of the other active members sees the new information, they
continue to drop out of the LAG. When all the members have dropped out of
the LAG, they form an aggregate with the new information.
Static LAGS
A static LAG is no different from a dynamically configured LAG. All the
requirements for the member ports hold true (member ports must be
physical, same speed, and so on). The only difference is this LAG has an
additional parameter
static
which makes this LAG not require a partner
system to be able to aggregate it's member ports.
A static LAG does not transmit or process received LACPDUs, that is, the
member ports do not transmit LACPDUs and all the LACPDUs it may
receive are dropped. A dropped counter is maintained to count the number of
such PDUs.
Configured members are added to the LAG (active participation)
immediately if the LAG is configured to be static. There is no wait time
before we add the port to the LAG.
2CSPC4.XModular-SWUM200.book Page 573 Thursday, March 10, 2011 11:18 AM