Users Guide

Port Channel Interfaces
On an Aggregator, port channels are auto-congured as follows:
• All 10GbE uplink interfaces (ports 33 to 56) are auto-congured to belong to the same 10GbE port channel (LAG 128).
• Server-facing interfaces (ports 1 to 32) auto-congure in LAGs (1 to 127) according to the NIC teaming conguration on the
connected servers.
Port channel interfaces support link aggregation, as described in IEEE Standard 802.3ad. .
NOTE: A port channel may also be referred to as a link aggregation group (LAG).
Port Channel Denitions and Standards
Link aggregation is dened by IEEE 802.3ad as a method of grouping multiple physical interfaces into a single logical interface—a link
aggregation group (LAG) or port channel. A LAG is “a group of links that appear to a MAC client as if they were a single link”
according to IEEE 802.3ad. In Dell Networking OS, a LAG is referred to as a port channel interface.
A port channel provides redundancy by aggregating physical interfaces into one logical interface. If one physical interface goes down
in the port channel, another physical interface carries the trac.
Port Channel Benets
A port channel interface provides many benets, including easy management, link redundancy, and sharing.
Port channels are transparent to network congurations and can be modied and managed as one interface.
With this feature, you can create larger-capacity interfaces by utilizing a group of lower-speed links. For example, you can build a 40-
Gigabit interface by aggregating four 10-Gigabit Ethernet interfaces together. If one of the four interfaces fails, trac is redistributed
across the three remaining interfaces.
Port Channel Implementation
An Aggregator supports only port channels that are dynamically congured using the link aggregation control protocol (LACP). For
more information, refer to Link Aggregation. Statically-congured port channels are not supported.
The table below lists out the number of port channels per platform.
Table 7. Number of Port Channels
Platform Port-channels Members/Channel
M IO Aggregator 128 16
As soon as a port channel is auto-congured, the Dell Networking OS treats it like a physical interface. For example, IEEE 802.1Q
tagging is maintained while the physical interface is in the port channel.
Member ports of a LAG are added and programmed into hardware in a predictable order based on the port ID, instead of in the order
in which the ports come up. With this implementation, load balancing yields predictable results across switch resets and chassis
reloads.
A physical interface can belong to only one port channel at a time.
Each port channel must contain interfaces of the same interface type/speed.
Port channels can contain a mix of 1000 or 10000 Mbps Ethernet interfaces . The interface speed (100, 1000, or 10000 Mbps) used
by the port channel is determined by the rst port channel member that is physically up. Dell Networking OS disables the interfaces
that do not match the interface speed set by the rst channel member. That rst interface may be the rst interface that is
physically brought up or was physically operating when interfaces were added to the port channel. For example, if the rst
100
Interfaces