Juniper Networks EX2500 Manuale Utente
EX2500 Ethernet Switch Configuration Guide
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Link Aggregation Control Protocol
A port’s Link Aggregation Identifier (LAG ID) determines how the port can be
aggregated. The Link Aggregation ID (LAG ID) is constructed mainly from the
system ID and the port’s admin key, as follows:
aggregated. The Link Aggregation ID (LAG ID) is constructed mainly from the
system ID and the port’s admin key, as follows:
System ID—An integer value based on the switch’s MAC address and the
system priority assigned in the CLI.
system priority assigned in the CLI.
Admin key—An integer value (13-65535) for the port that you can configure in
the CLI. Each switch port that participates in the same LACP trunk group must
have the same admin key value. The admin key is local significant, which means
the partner switch does not need to use the same admin key value.
the CLI. Each switch port that participates in the same LACP trunk group must
have the same admin key value. The admin key is local significant, which means
the partner switch does not need to use the same admin key value.
For example, consider two switches, an Actor (the EX2500 switch) and a Partner
(another switch), as shown in Table 11.
(another switch), as shown in Table 11.
In the configuration shown in Table 11, Actor switch port 7 and port 8 aggregate to
form an LACP trunk group with Partner switch port 1 and port 2.
form an LACP trunk group with Partner switch port 1 and port 2.
LACP automatically determines which member links can be aggregated and then
aggregates them. It provides for the controlled addition and removal of physical
links for the link aggregation.
aggregates them. It provides for the controlled addition and removal of physical
links for the link aggregation.
Each port on the switch can have one of the following LACP modes:
off
(default)—The user can configure this port in to a regular static trunk group.
active
—The port is capable of forming an LACP trunk. This port sends LACPDU
packets to partner system ports.
passive
—The port is capable of forming an LACP trunk. This port responds only
to the LACPDU packets sent from an LACP active port.
Each active LACP port transmits LACP data units (LACPDUs), while each passive
LACP port listens for LACPDUs. During LACP negotiation, the admin key is
exchanged. The LACP trunk group is enabled as long as the information matches at
both ends of the link. If the admin key value changes for a port at either end of the
link, that port’s association with the LACP trunk group is lost.
LACP port listens for LACPDUs. During LACP negotiation, the admin key is
exchanged. The LACP trunk group is enabled as long as the information matches at
both ends of the link. If the admin key value changes for a port at either end of the
link, that port’s association with the LACP trunk group is lost.
NOTE:
LACP implementation in the EX2500 switch does not support the Churn
machine, an option used to detect if the port is operable within a bounded time
period between the actor and the partner. Only the Marker Responder is
implemented, and there is no marker protocol generator.
period between the actor and the partner. Only the Marker Responder is
implemented, and there is no marker protocol generator.
Table 11: Actor vs. Partner LACP Configuration
Actor Switch
Partner Switch 1
Port 7 (admin key = 100)
Port 1 (admin key = 50)
Port 8 (admin key = 100)
Port 2 (admin key = 50)