Dell 6.2 Chapte r 9

DellPowerConnect W- Series ArubaOS 6.2 | User Guide LinkAggregation Control Pr otocol (LACP) | 148
Chapte r 9
Link Aggre gation Control P rotocol (LACP)
Dell’si mplementationo f Link Aggregation Control Protocol (LACP) is based on the standards specified in 802.3ad.
LACP provides a standardized meansfor exchanging information, with partner systems, to form a linkaggregation
group(LAG). LA CP avoids port channel misconfiguration.
Two devices (actor and partner)exchange LACP data units (DUs) in the process of forming a LAG.Once multiple
ports in the system have the same actor system ID, actor key, partner system ID, and partner key, they belong to the
same LAG.
The maximumnumber of supported port-channels is 8. With the introduction of LACP, this number remains the
same. In essence, a port-channelgroup (LAG) is created either statically or dynamically via LACP. This c hapter
contains:
l"UnderstandingLACP Best Practices and Exceptions" on page 148
l"ConfiguringLACP" on page 1 49
l"LACP Sample Configuration"on page 15 0
Understanding L ACP Best Practices and Exceptio ns
lLACP is disabled by default
lLACP depends onperiodical Tx/Rx of LACP data units (LACPDU). Any failuresare noticed immediately and
that port is removedfrom the LAG
lThe maximumLAG supported per system is 8 groups; each group can be created statically or via LA CP
lEach LAG can have up to 8 member ports
lThe LAG groupidentificatio n(ID )range is 0 to 7 for both static (port-channel) andLACP groups
lWhena port is added to a LA CP LAG, it inherits the port-channel’sproperties (i.e. VLAN membership, trunk
status etc)
lWhena port is added to LACP LAG, the port’s property (i.e. speed) is compared to the existing port properties.
If therei s a mismatch,t hecommand is rejected.
lThe LACP commands can not be configuredon a port that is already a member of a static port-channel.
Similarly,if the group assigned in the command lacp group <number>already contains static port members,
the commandi s rejected.
lThe port uses the group numberas i t’s actor admin key.
lBy default,all ports use long ti meout values (90 seconds).
lThe output of the command show interface port-channelnowi ndicates if the LAG is created by LACP
(dynamic) or static configuration. If the LAG is created via LACP, you can not add/deleteany ports underthat
port channel.All other commands are allowed.