Specifications

Link Aggregation Control Protocol (LACP)
SecureStack A2 Usage Considerations
SecureStack A2 Configuration Guide 3-49
3.5.3 SecureStack A2 Usage Considerations
In normal usage (and typical implementations) there is no need to modify any of the default LACP
parameters on the SecureStack device. The default values will result in the maximum number of
aggregations possible. If the switch is placed in a configuration with its peers not running the
protocol, no dynamic link aggregations will be formed and the switch will function normally (that
is, will block redundant paths). For information about building static aggregations, refer to set lacp
static (Section 3.5.4.6).
Each SecureStack A2 unit provides six virtual link aggregator ports, which are designated in the
CLI as lag.0.1 through lag.0.6. Each LAG can have up to four associated physical ports. Once
underlying physical ports (that is, fe.x.x or ge.x.x) are associated with an aggregator port, the
resulting aggregation will be represented as one LAG with a lag.0.x port designation. LACP
determines which underlying physical ports are capable of aggregating by comparing operational
keys. Aggregator ports allow only underlying ports with keys matching theirs to join their LAG.
LACP uses a system priority value to build a LAG ID, which determines aggregation precedence.
If there are two partner devices competing for the same aggregator, LACP compares the LAG IDs
for each grouping of ports. The LAG with the lower LAG ID is given precedence and will be
allowed to use the aggregator.
Actor and Partner An actor is the local device sending LACPDUs. Its protocol partner is the
device on the other end of the link aggregation. Each maintains current
status of the other via LACPDUs containing information about their ports’
LACP status and operational state.
Admin Key Value assigned to aggregator ports and physical ports that are candidates
for joining a LAG. The LACP implementation on SecureStack A2 devices will
use this value to form an oper key and will determine which underlying
physical ports are capable of aggregating by comparing oper keys.
Aggregator ports allow only underlying ports with oper keys matching theirs
to join their LAG.
System Priority Value used to build a LAG ID, which determines aggregation precedence. If
there are two partner devices competing for the same aggregator, LACP
compares the LAG IDs for each grouping of ports. The LAG with the lower
LAG ID is given precedence and will be allowed to use the aggregator.
NOTE: Only one LACP system priority can be set on a
SecureStack A2 device, using either the set lacp asyspri
command (Section 3.5.4.3), or the set port lacp command
(Section 3.5.4.11).
Table 3-3 LACP Terms and Definitions (Continued)
Term Definition