Prerequisites; Link Aggregation Configuration Default Configuration - Foundry Networks NetIron M2404C User Manual

Foundry NetIron M2404C and M2404F Metro Access Switches
If, as a result of an LACP exchange, the local LACP system decides to aggregate the port with one
or more other port, it includes the port in an appropriate dynamic LAG. If an appropriate LAG does
not exist, it is created.
If no answer is received during the first 5 seconds after connection, or if upon the completion of an
LACP exchange, the LACP assumes that the port cannot be aggregated, the port acts a single non-
aggregated port.
If a connection between two LACP ports is recognized, one of the two ports will act as the active
port, and the other as the passive port. Regardless of the ports' initial settings before the connection,
the decision for determining which of the ports will be active depends primarily on the ports'
priorities, secondarily on LACP systems' priorities, and thirdly on LACP systems' IDs.
The connected ports exchange frames every 30 seconds to verify that the LACP connection is still
valid, and that the partner's settings have not been changed.
If the settings of an LACP port are changed administratively, it sends a frame to notify its partner
about this change, and the process of updating operative parameters on the connected pair is
repeated. When this update is completed, the LACP system may decide either to exclude an
affected port from current LAG or move it to another LAG.
If a port that is included in a dynamic LAG is disconnected, the LACP immediately excludes this
port from its LAG.
If the LACP port A that is connected to a partner LACP port B stops receiving periodic LACP
frames (for example, if LACP is disabled on a partner system, or on a partner port B), the LACP
port A will be excluded from its dynamic LAG upon expiration of a 90-second timeout.
If no more ports remain in a dynamic LAG, it is removed.

Prerequisites

The following guidelines apply to LAG configuration.
•
The user needs not make changes to existing higher-layer protocols or applications in order to
use Link Aggregation.
•
Links that cannot take part in Link Aggregation - due to their inherent capabilities or the
capabilities of the devices to which they are attached, or due to management configuration -
operate as normal, individual links.
•
LACP supports only point-to-point full-duplex links. Aggregations among more than two
devices (multipoint aggregations) and half-duplex operation are not supported.
•
When the device is connected to a LAN and Spanning Tree protocol is not active, physically
connect the aggregated ports ONLY after LAG configuration is completed.
NOTE

Link Aggregation Configuration Default Configuration

Table 9 shows the default Link Aggregation configuration.
Link Aggregation Groups (LAG)
For more details on how to configure LAG with H-VPLS, please refer to the
"Configuring Multiprotocol Label Switching (MPLS) and Hierarchical Virtual
Private LAN Services (H-VPLS)" chapter.
© 2008 Foundry Networks, Inc.
Configuring Interfaces (Rev. 03)
Page 29 of 57