Specifications

Chapter 5. IBM System Networking RackSwitch implementation 175
Verify the trunk group parameters by running show portchannel <number>
(Example 5-22).
Example 5-22 Display trunk group parameters
AGG-1#show portchannel 1
Protocol - Static
Current settings: enabled
ports: 17, 18
Current L2 trunk hash settings:
smac
Current L3 trunk hash settings:
sip dip
Current ingress port hash: enabled
Current L4 port hash: disabled
AGG-1#
Dynamic trunks
Link Aggregation Control Protocol (LACP) is an IEEE 802.3ad standard for grouping several
physical ports into one logical port (known as a dynamic trunk group or Link Aggregation
group) with any device that supports the standard. See IEEE 802.3ad-2002 for a full
description of the standard.
The 802.3ad standard allows standard Ethernet links to form a single Layer 2 link by using
the LACP. Link aggregation is a method of grouping physical link segments of the same
media type and speed in full duplex, and treating them as if they were part of a single, logical
link segment. If a link in a LACP trunk group fails, traffic is reassigned dynamically to the
remaining links of the dynamic trunk group.
A port’s Link Aggregation Identifier (LAG ID) determines how the port can be aggregated. The
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.
Admin key A port’s Admin key is an integer value (1 - 65535) 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.
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.
Each port on the switch can have one of the following LACP modes:
Off (default) The user can configure this port in a regular static trunk group.
Active The port can form an LACP trunk. This port sends LACPDU packets to
partner system ports.
Passive The port can form an LACP trunk. This port responds only to the
LACPDU packets sent from an LACP active port.