IronPort Systems 4108GL - Manual (Page 221)

11-23
Optimizing Port Usage Through Traffic Control and Port Trunking
Port Trunking
Po
rts: T
ra
ffic
C
o
n
tr
o
l
an
d T
run
ki
ng
Enabling a Dynamic LACP Trunk Group. In the default port configura-
tion, all ports on the switch are set to LACP passive. However, to enable the
switch to automatically form a trunk group that is dynamic on both ends of
the link, the ports on one end of a set of links must be LACP active. The ports
on the other end can be either LACP active or LACP passive. This command
enables the switch to automatically establish a (dynamic) LACP trunk group
when the device on the other end of the link is configured for LACP passive.
Figure 11-12. Example of Criteria for Automatically Forming a Dynamic LACP Trunk
Syntax: interface <port-list> lacp active
This example uses ports C4 and C5 to enable a dynamic LACP trunk group.
HP4108(config)# interface c4-c5 lacp active
Switch “A”
with ports set
to LACP
passive (the
default). Switch “B”
with ports set
to LACP
passive (the
default).
Dynamic LACP trunk cannot automatically form because both
ends of the links are LACP passive.
(In this case STP blocking is needed to prevent a loop.
Switch “A”
with ports set
to LACP
active. Switch “B”
with ports set
to LACP
passive (the
default).
Dynamic LACP trunk automatically forms because both
ends of the links are LACP and at least one end is LACP
active. (STP is not needed, and the clear advantages are
increased bandwidth and fault-tolerance.)