Interface option
Dynamic LACP trunk
group
Static LACP trunk group Static non-protocol
CLI
show trunk
No
Yes
Yes
CLI
show interfaces
No
Yes
Yes
CLI
show lacp
Yes
Yes
No
CLI
show spanning-
tree
No
Yes
Yes
CLI
show igmp
No
Yes
Yes
CLI
show config
No
Yes
Yes
Outbound traffic distribution across trunked links
The two trunk group options (LACP and trunk) use SA/DA pairs for distributing outbound traffic over trunked links.
That is, the switch sends traffic from the same source address to the same destination address through the same
trunked link, and may also send traffic from the same source address to a different destination address through
the same link or a different link, depending on the mapping of path assignments among the links in the trunk.
Likewise, the switch distributes traffic for the same destination address but from different source addresses
through links depending on the path assignment.
The load-balancing is done on a per-communication basis. Otherwise, traffic is transmitted across the same path
as shown in the figure below. That is, if Client A attached to Switch 1 sends five packets of data to Server A
attached to Switch 2, the same link is used to send all five packets. The SA/DA address pair for the traffic is the
same. The packets are not evenly distributed across any other existing links between the two switches; they all
take the same path.
Figure 16: Example: of single path traffic through a trunk
The actual distribution of the traffic through a trunk depends on a calculation using bits from the SA/DA. When an
IP address is available, the calculation includes the last five bits of the IP source address and IP destination
address; otherwise, the MAC addresses are used. The result of that process undergoes a mapping that
determines which link the traffic goes through. If you have only two ports in a trunk, it is possible that all the traffic
will be sent through one port even if the SA/DA pairs are different. The more ports you have in the trunk, the more
likely it is that the traffic will be distributed among the links.
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Aruba 2930F / 2930M Management and Configuration Guide
for ArubaOS-Switch 16.08
