Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 515

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 10 or 40 Gigabit Ethernet interfaces. The interface speed (10, 40 Gbps) the port channel uses is determined by the first port channel member that is physically up. The system 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 10-Gigabit Ethernet interface, all interfaces at 40Gbps are kept up, and all 10/40 GbE interfaces that are not set to 10000 speed or auto negotiate are disabled. The system brings up 10/40 GbE 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. 10/40 Gbps Interfaces in Port Channels When both 10/40 interfaces GigE 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 configuration becomes the common speed of the port channel. If the other interfaces configured in that port channel are configured with a different speed, the system disables them. 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) • Configuring the Minimum Oper Up Links in a Port Channel (optional) • Adding or Removing a Port Channel from a VLAN (optional) • Assigning an IP Address to a Port Channel (optional) • Deleting or Disabling a Port Channel (optional) • Load Balancing Through Port Channels (optional) Interfaces 515