Service Manual

Port Channel Implementation
Dell Networking OS supports static and dynamic port channels.
• Static — Port channels that are statically congured.
• Dynamic — Port channels that are dynamically congured using the link aggregation control protocol (LACP). For details, refer
to Link Aggregation Control Protocol (LACP).
There are 128 port-channels with 16 members per channel.
As soon as you congure 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 10, 100, or 1000 Mbps Ethernet interfaces and Gigabit Ethernet interfaces. The interface speed
(10, 100, or 1000 Mbps) the port channel uses is determined by the rst port channel member that is physically up. Dell Networking
OS disables the interfaces that do match the interface speed that the rst channel member sets. 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 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 10/100/1000 interfaces that are set to auto negotiate so that their speed is identical to the speed of
the rst channel member in the port channel.
1/10/40 Gbps Interfaces in Port Channels
When 1/10/40 Gbps interfaces are added to a port channel, the interfaces must share a common speed. When interfaces have a
congured speed dierent from the port channel speed, the software disables those interfaces.
The common speed is determined when the port channel is rst enabled. At that time, the software checks the rst interface listed
in the port channel conguration. If you enabled that interface, its speed conguration becomes the common speed of the port
channel. If the other interfaces congured in that port channel are congured with a dierent speed, Dell Networking OS disables
them.
Conguration Tasks for Port Channel Interfaces
To congure a port channel (LAG), use the commands similar to those found in physical interfaces. By default, no port channels are
congured in the startup conguration.
These are the mandatory and optional conguration tasks:
• Creating a Port Channel (mandatory)
• Adding a Physical Interface to a Port Channel (mandatory)
• Reassigning an Interface to a New Port Channel (optional)
• Conguring 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)
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Interfaces