Junos® OS Ethernet Interfaces Configuration ... - Juniper Networks

LACP is defined in IEEE 802.3ad, Aggregation of Multiple Link Segments.
LACP was designed to achieve the following:
• Automatic addition and deletion of individual links to the aggregate bundle without
user intervention
• Link monitoring to check whether both ends of the bundle are connected to the correct
group
Copyright © 2012, Juniper Networks, Inc.
The Junos OS implementation of LACP provides link monitoring but not automatic addition
and deletion of links.
The LACP mode can be active or passive. If the actor and partner are both in passive
mode, they do not exchange LACP packets, which results in the aggregated Ethernet
links not coming up. If either the actor or partner is active, they do exchange LACP packets.
By default, LACP is turned off on aggregated Ethernet interfaces. If LACP is configured,
it is in passive mode by default. To initiate transmission of LACP packets and response
to LACP packets, you must configure LACP in active mode.
To enable LACP active mode, include the lacp statement at the [edit interfaces
interface-name aggregated-ether-options] hierarchy level, and specify the active option:
[edit interfaces interface-name aggregated-ether-options]
lacp {
active;
}
NOTE: The LACP process exists in the system only if you configure the system
in either active or passive LACP mode.
To restore the default behavior, include the lacp statement at the [edit interfaces
interface-name aggregated-ether-options] hierarchy level, and specify the passive option:
[edit interfaces interface-name aggregated-ether-options]
lacp {
passive;
}
Starting with Junos OS release 12.2, you can also configure LACP to override the IEEE
802.3ad standard and to allow the standby link always to receive traffic. Overriding the
default behavior facilitates subsecond failover.
To override the IEEE 802.3ad standard and facilitate subsecond failover, include the
fast-failover statement at the [edit interfaces interface-name aggregated-ether-options
lacp] hierarchy level.
For more information, see the following sections:
• Configuring the LACP Interval on page 114
• Configuring LACP Link Protection on page 114
• Tracing LACP Operations on page 117
Chapter 4: Configuring Aggregated Ethernet Interfaces
113