Administrator Guide
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
operational interface in the port channel is a TenGigabit Ethernet interface, all interfaces at 1000 Mbps are kept up, and all
100/1000/10000 interfaces that are not set to 1000 Mbps speed or auto negotiate are disabled.
1GbE and 10GbE Interfaces in Port Channels
When both Gigabit and TenGigabitEthernet interfaces are added to a port channel, the interfaces must share a common speed.
When interfaces have a congured speed dierent 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 conguration. If that interface is enabled, its speed conguration becomes the common speed of the port
channel. If the other interfaces congured in that port channel are congured with a dierent speed, Dell Networking OS disables
them.
For example, if four interfaces (TenGig 0/1, 0/2, 0/3 and 0/4) in which TenGig 0/1and TenGig 0/2 are set to speed 1000 Mb/s and
the TenGig 0/3 and TenGig0/4 are set to 10000 Mb/s, with all interfaces enabled, and you add them to a port channel by entering
channel-member tengigabitethernet 0/1-4 while in port channel interface mode, and the Dell Networking OS determines
if the rst interface specied (TenGig 0/0) is up. After it is up, the common speed of the port channel is 1000 Mb/s. Dell Networking
OS disables those interfaces congured with speed 10000 Mb/s or whose speed is 10000 Mb/s as a result of auto-negotiation.
In this example, you can change the common speed of the port channel by changing its conguration so the rst enabled interface
referenced in the conguration is a 1000 Mb/s speed interface. You can also change the common speed of the port channel by
setting the speed of the TenGig 0/1 interface to 1000 Mb/s.
Uplink Port Channel: VLAN Membership
The tagged VLAN membership of the uplink LAG is automatically congured based on the VLAN conguration of all server-facing
ports (ports 1 to 32).
The untagged VLAN used for the uplink LAG is always the default VLAN 1.
Server-Facing Port Channel: VLAN Membership
The tagged VLAN membership of a server-facing LAG is automatically congured based on the server-facing ports that are
members of the LAG.
The untagged VLAN of a server-facing LAG is auto-congured based on the untagged VLAN to which the lowest numbered server-
facing port in the LAG belongs.
Displaying Port Channel Information
To view the port channel’s status and channel members in a tabular format, use the show interfaces port-channel
brief command in EXEC Privilege mode.
Dell#show int port brief
Codes: L - LACP Port-channel
LAG Mode Status Uptime Ports
1 L2 down 00:00:00 Te 0/16 (Down)
Dell#
94
Interfaces