Concept Guide

Many of the commands supported on physical interfaces are also supported on a Loopback interface.
Null Interfaces
The Null interface is another virtual interface. There is only one Null interface. It is always up, but no trac is transmitted through this
interface.
To enter INTERFACE mode of the Null interface, use the following command.
• Enter INTERFACE mode of the Null interface.
CONFIGURATION mode
interface null 0
The only congurable command in INTERFACE mode of the Null interface is the ip unreachable command.
Port Channel Interfaces
Port channel interfaces support link aggregation, as described in IEEE Standard 802.3ad.
This section covers the following topics:
• Port Channel Denition and Standards
• Port Channel Benets
• Port Channel Implementation
• Conguration Tasks for Port Channel Interfaces
Port Channel Denition and Standards
Link aggregation is dened by IEEE 802.3ad as a method of grouping multiple physical interfaces into a single logical interface—a link
aggregation group (LAG) or port channel.
A LAG is “a group of links that appear to a MAC client as if they were a single link” according to IEEE 802.3ad. In Dell EMC Networking OS,
a LAG is referred to as a port channel interface.
A port channel provides redundancy by aggregating physical interfaces into one logical interface. If one physical interface goes down in the
port channel, another physical interface carries the trac.
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. For example, you congure
one IP address for the group and that IP address is used for all routed trac 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 5-Gigabit
interface by aggregating ve 1-Gigabit Ethernet interfaces together. If one of the ve interfaces fails, trac is redistributed across the
remaining interfaces.
Port Channel Implementation
Dell EMC 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, see Link
Aggregation Control Protocol (LACP).
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Interfaces