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-congures with link aggregation groups (LAGs) as follows:
• All uplink ports are automatically congured in a single port channel (LAG 128).
• Server-facing LAGs are automatically congured if you congure server for link aggregation control protocol (LACP)-based NIC
teaming (Network Interface Controller (NIC) Teaming).
No manual conguration is required to congure 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-conguring
dynamic LAGs. Use CLI commands to display LACP information, clear port-channel counters, and debug LACP operation for auto-
congured LAG on an Aggregator.
The Dell Networking OS implementation of LACP is based on the standards specied in the IEEE 802.3: “Carrier sense multiple
access with collision detection (CSMA/CD) access method and physical layer specications.”
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 congure as LACP-capable.
NOTE: In Standalone, VLT, and Stacking modes, you can congure 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