Dell Force10 Z9000 FTOS Configuration Guide for Z9000 System - Page 385

Null Interfaces The Null interface is another virtual interface created by the E-Series software. There is only one Null interface. It is always up, but no traffic is transmitted through this interface. To enter the INTERFACE mode of the Null interface, use the following command in the CONFIGURATION mode: Command Syntax interface null 0 Command Mode CONFIGURATION Purpose Enter the INTERFACE mode of the Null interface. The only configurable command in the 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 task list 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 FTOS, 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 For the E-Series, 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. Interfaces | 385