Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 478

• 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 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. 478 Interfaces