Administrator Guide

Port Channel Benefits
A port channel interface provides many benefits, including easy management, link redundancy, and sharing.
Port channels are transparent to network configurations and can be modified and managed as one interface. For example, you configure
one IP address for the group and that IP address is used for all routed traffic on the port channel.
With this feature, you can create larger-capacity interfaces by utilizing a group of lower-speed links. For example, you can build a 5-Gigabit
interface by aggregating five 1-Gigabit Ethernet interfaces together. If one of the five interfaces fails, traffic is redistributed across the
remaining interfaces.
Port Channel Implementation
Dell EMC Networking OS supports static and dynamic port channels.
• Static — Port channels that are statically configured.
• Dynamic — Port channels that are dynamically configured using the link aggregation control protocol (LACP). For details, see Link
Aggregation Control Protocol (LACP).
The port channel ID ranges from 1 to 128.
As soon as you configure a port channel, Dell EMC 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 the 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 device 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 1G/10G/40G. The interface speed that the port channel uses is determined by the first port channel
member that is physically up. Dell EMC Networking OS disables the interfaces that do not match the interface speed that the first channel
member sets. That first interface may be either the interface that is physically brought up first or was physically operating when interfaces
were added to the port channel. For example, if the first operational interface in the port channel is a Tengigabit Ethernet interface, all
interfaces at 10000 Mbps are kept up, and all other interfaces that are not set to 10G speed or auto negotiate are disabled.
Dell EMC Networking OS brings up the interfaces that are set to auto negotiate so that their speed is identical to the speed of the first
channel member in the port channel.
Interfaces in Port Channels
When interfaces are added to a port channel, the interfaces must share a common speed. When interfaces have a configured speed
different from the port channel speed, the software disables those interfaces.
The common speed is determined when the port channel is first enabled. Then, the software checks the first interface listed in the port
channel configuration. If you enabled that interface, its speed configuration becomes the common speed of the port channel. If the other
interfaces configured in that port channel are configured with a different speed, Dell EMC Networking OS disables them.
Port channels can contain a mix of 1G/10G/40G. The interface speed that the port channel uses is determined by the first port channel
member that is physically up. Dell EMC Networking OS disables the interfaces that do not match the interface speed that the first channel
member sets. That first interface may be either the interface that is physically brought up first or was physically operating when interfaces
were added to the port channel. For example, if the first operational interface in the port channel is a Tengigabit Ethernet interface, all
interfaces at 10000 Mbps are kept up, and all other interfaces that are not set to 10G speed or auto negotiate are disabled.
Dell EMC Networking OS brings up the interfaces that are set to auto negotiate so that their speed is identical to the speed of the first
channel member in the port channel.
Configuration Tasks for Port Channel Interfaces
To configure a port channel (LAG), use the commands similar to those found in physical interfaces. By default, no port channels are
configured in the startup configuration.
These are the mandatory and optional configuration tasks:
• Creating a Port Channel (mandatory)
• Adding a Physical Interface to a Port Channel (mandatory)
• Reassigning an Interface to a New Port Channel (optional)
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Interfaces