Brocade Converged Enhanced Ethernet Administrator's Guide v6.1.2_cee (53-1001258-01, June 2009)

Table Of Contents
Converged Enhanced Ethernet Administrator’s Guide 71
53-1001258-01
LACP configuration guidelines and restrictions
5
LACP configuration guidelines and restrictions
Follow these LACP configuration guidelines and restrictions when configuring LACP.
NOTE
This section applies to standards-based and Brocade-proprietary LAG configurations except where
specifically noted otherwise.
NOTE
All ports on the Brocade 8000 CEE switch can operate only in full-duplex mode.
An LACP-enabled link is assigned an administrative key and all local links on the switch that
share the same administrative key can potentially be aggregated. A system ID and the
administrative key are combined to form a unique identifier for neighboring devices.
Layer 2 control protocols
Layer 2 control protocols such as Spanning Tree Protocol (STP), Rapid STP (RSTP), and Multiple
STP (MSTP) are transparent to the operation of LACP. These protocols see a LAG as a logical
interface. When an STP bridged protocol data unit (BPDU) needs to be transmitted, the LAG
has the responsibility of choosing one of its operationally active member links to transmit it.
VLANs
- Before being aggregated, links cannot be members of a VLAN.
- A VLAN sees a LAG as a logical interface.
- All LAG member links are configured with the same VLAN ID.
QoS
In the Fabric OS version 6.1.2_cee release, QoS commands for a LAG need to be specified on
each LAG member link, instead of on the logical LAG interface (port-group). Additionally, the
QoS commands specified on each LAG member link need to be the same on each link.
Brocade-proprietary LAGs only
All LAG member links need to be part of the same port-group.
Switchport interfaces
Interfaces configured as “switchport” interfaces cannot be aggregated into a LAG. However, a
LAG can be configured as a switchport.
LAG interface statistics and individual link statistics
LAG statistics and individual link statistics comply with standard RMON and MIB2 interface
statistics. Cumulative statistics of all the LAG member links are maintained for the LAG.
Individual link statistics are also maintained. The statistical counters of a LAG member link
start when the link becomes a member of the LAG and stop when the link goes out of the LAG.
To retain the history of individual links, individual link statistical counters keep generating
individual link statistics even when the link is part of a LAG.
IEEE 802.3ad specifies that an LACP-enabled link can be configured as either active or
passive. However, if both sides of the link are configured as passive, the LACP protocol is not
initiated and the LAG is not formed.