Loopback Interfaces
A Loopback interface is a virtual interface in which the software emulates an interface. Packets routed to it are processed
locally.
Because this interface is not a physical interface, you can configure routing protocols on this interface to provide protocol
stability. You can place Loopback interfaces in default Layer 3 mode.
To configure, view, or delete a Loopback interface, use the following commands.
•
Enter a number as the Loopback interface.
CONFIGURATION mode
interface loopback number
The range is from 0 to 16383.
•
View Loopback interface configurations.
EXEC mode
show interface loopback number
•
Delete a Loopback interface.
CONFIGURATION mode
no interface loopback number
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 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 Dell
Networking OS, a LAG is referred to as a port channel interface.
Interfaces
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