Brocade 6910 Ethernet Access Switch Diagnostic Guide (Supporting R2.2.0.0) - Manual (Page 40)

30 Brocade 6910 Ethernet Access Switch Diagnostic Guide
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DRAFT: BROCADE CONFIDENTIAL
LACP trunking
Common diagnostic scenarios
• Spanning Tree loops.
• Spanning Tree reacts to topology changes and port flapping.
• Port flapping can trigger a new Spanning Tree learning process.
LACP trunking
The Link Aggregation Control Protocol (LACP) allows ports on both sides of a redundant link to
automatically configure themselves into a trunk link (aggregate link), eliminating the need for
manual configuration. LACP has two modes:
• Active mode – When active link aggregation is enabled, the Brocade port can exchange
standard LACP Data Unit (LACPDU) messages to negotiate trunk group configuration with the
port on the other side of the link. In addition, the Brocade port actively sends LACPDU
messages on the link to search for a link aggregation partner at the other end of the link, and
can initiate an LACPDU exchange to negotiate link aggregation parameters with an
appropriately configured remote port.
• Passive mode – In passive link aggregation, the Brocade port can exchange LACPDU messages
with the port at the remote end of the link, but this port cannot search for a link aggregation
port or initiate negotiation of an aggregate link. In passive mode, the port at the remote end of
the link must initiate the LACPDU exchange.
When you enable link aggregation on a group of Brocade ports, the Brocade ports can negotiate
with the ports at the remote ends of the links to establish trunk groups.
Trunk show commands
The following show commands display information about trunking configurations.
show lacp internal
Syntax: show lacp [port-channel] internal
port-channel - Local identifier for a link aggregation group. (Range: 1-5)
This command displays trunk information for configuration settings and the operational state for
the local side.
Console# show lacp 1 internal
Port Channel : 1
-------------------------------------------------------------------------
Oper Key : 3
Admin Key : 0
Eth 1/ 1
-------------------------------------------------------------------------
LACPDUs Internal : 30 seconds
LACP System Priority : 32768
LACP Port Priority : 32768
Admin Key : 3
Oper Key : 3
Admin State : defaulted, aggregation, long timeout, LACP-activity
Oper State : distributing, collecting, synchronization,
aggregation, long timeout, LACP-activity