Service Manual

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 50-Gigabit interface by aggregating five 10-Gigabit Ethernet interfaces
together. If one of the five interfaces fails, traffic is redistributed across the remaining interfaces.
Port Channel Implementation
Dell 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).
There are 128 port-channels with 16 members per channel.
As soon as you configure a port channel, 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 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 line card 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 1G/10G/40G. The interface speed (10, 100, or 1000 Mbps) the port
channel uses is determined by the first port channel member that is physically up. Dell Networking OS
disables the interfaces that do match the interface speed that the first channel member sets. That first
interface may be the first interface that is physically brought up 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 Gigabit Ethernet interface, all interfaces at 1000 Mbps are kept up, and all 10/100/1000
interfaces that are not set to 1000 speed or auto negotiate are disabled.
Dell Networking OS brings up the interfaces 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 10/40 Gbps 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. At that time, the software
checks the first interface listed in the port channel configuration. If you enabled that interface, its speed
Interfaces
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