Users Guide

11
Link Aggregation
Unlike IOA Automated modes (Standalone and VLT modes), the IOA Programmable MUX (PMUX) can
support multiple uplink LAGs. You can provision multiple uplink LAGs. The I/O Aggregator auto-
configures with link aggregation groups (LAGs) as follows:
• All uplink ports are automatically configured in a single port channel (LAG 128).
• Server-facing LAGs are automatically configured if you configure server for link aggregation control
protocol (LACP)-based NIC teaming (Network Interface Controller (NIC) Teaming).
No manual configuration is required to configure Aggregator ports in the uplink or a server-facing LAG.
NOTE: Static LAGs are not supported on the SMUX Aggregator.
NOTE: In order to avoid loops, only disjoint VLANs are allowed between the uplink ports/uplink
LAGs and uplink-to-uplink switching is disabled.
Supported Modes
Standalone, VLT, PMUX, Stacking
How the LACP is Implemented on an Aggregator
The LACP provides a means for two systems (also called partner systems) to exchange information
through dynamic negotiations to aggregate two or more ports with common physical characteristics to
form a link aggregation group.
NOTE: A link aggregation group is referred to as a port channel by the Dell Networking OS.
A LAG provides both load-sharing and port redundancy across stack units. An Aggregator supports LACP
for auto-configuring dynamic LAGs. Use CLI commands to display LACP information, clear port-channel
counters, and debug LACP operation for auto-configured LAG on an Aggregator.
The Dell Networking OS implementation of LACP is based on the standards specified in the IEEE 802.3:
“Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer
specifications.”
LACP functions by constantly exchanging custom MAC protocol data units (PDUs) across local area
network (LAN) Ethernet links. The protocol packets are only exchanged between ports that you configure
as LACP-capable.
Link Aggregation
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