Null Interfaces
The Null interface is another virtual interface. There is only one Null interface. It is always up, but no
traffic 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 configurable 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 Definition and Standards
•Port Channel Benefits
•Port Channel Implementation
•Configuration Tasks for Port Channel Interfaces

Port Channel Definition and Standards

Link aggregation is defined 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 the Dell 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 traffic.

Port Channel Benefits

A port channel interface provides many benefits, including easy management, link redundancy, and
sharing.
Port channels are transparent to network configurations and can be modified and managed as one
interface. For example, you configure one IP address for the group and that IP address is used for all
routed traffic on the port channel.
408 Interfaces