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-congures with link aggregation groups (LAGs) as follows:
All uplink ports are automatically congured in a single port channel (LAG 128).
Server-facing LAGs are automatically congured if you congure server for link aggregation control protocol (LACP)-based NIC
teaming (Network Interface Controller (NIC) Teaming).
No manual conguration is required to congure 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-conguring
dynamic LAGs. Use CLI commands to display LACP information, clear port-channel counters, and debug LACP operation for auto-
congured LAG on an Aggregator.
The Dell Networking OS implementation of LACP is based on the standards specied in the IEEE 802.3: “Carrier sense multiple
access with collision detection (CSMA/CD) access method and physical layer specications.
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 congure as LACP-capable.
NOTE: In Standalone, VLT, and Stacking modes, you can congure a maximum of 16 members in port-channel 128. In
PMUX mode, you can have multiple port-channels with up to 16 members per channel.
118
Link Aggregation