Users Guide

Port Channel Benets
A port channel interface provides many benets, including easy management, link redundancy, and sharing.
Port channels are transparent to network congurations and can be modied and managed as one interface.
With this feature, you can create larger-capacity interfaces by utilizing a group of lower-speed links. For example, you can build a 40-Gigabit
interface by aggregating four 10-Gigabit Ethernet interfaces together. If one of the four interfaces fails, trac is redistributed across the
three remaining interfaces.
Port Channel Implementation
An Aggregator supports only port channels that are dynamically congured using the link aggregation control protocol (LACP). For more
information, refer to Link Aggregation. Statically-congured port channels are not supported.
The table below lists out the number of port channels per platform.
Table 9. Number of Port Channels
Platform Port-channels Members/Channel
M IO Aggregator 128 16
As soon as a port channel is auto-congured, the 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 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 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 that interface is enabled, 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.
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 specied (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 congured with speed 10000 Mb/s or whose speed is 10000 Mb/s as a result of auto-negotiation.
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Interfaces