CLI Reference Guide

590 Port Channel Commands
Static LAGS
A static LAG is fundamentally 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 running Link Aggregation Control Protocol (LACP) 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.
A LAG can be either static or dynamic, but not both. It cannot have some
member ports participate in the protocol while other member ports do not
participate. Additionally, it is not possible to change a LAG from static to
dynamic via the CLI. You must remove the member ports from the static
LAG and then add them to the dynamic LAG.
VLANs and LAGs
When physical interfaces are added to a LAG, they are removed from all
existing physical link VLAN membership and take on the VLAN membership
of the LAG. When members are removed from a LAG, the members regain
the physical interface VLAN membership as per the configuration file.
LAG Thresholds
In many implementations, a LAG is declared as up if any one of its member
ports is active. This enhancement provides configurability for the minimum
number of member links to be active to declare a LAG up. Network
administrators can also utilize this feature to automatically declare a LAG
down when only some of the links have failed.
2CSNXXX_SWUM200.book Page 590 Tuesday, December 10, 2013 1:22 PM