Dell PowerConnect 6248 Command Line Interface Guide - Page 141

CLI Command Modes Since the set of CLI commands is very large, the CLI is structured as a command-tree hierarchy, where related command sets are assigned to command modes for easier access. At each level, only the commands related to that level are available to the user and only those commands are shown in the context sensitive help for that level. In this guide, commands are organized into three categories: • Layer 2 (Data Link Layer) commands • Layer 3 (Network Layer) commands • Utility Commands Layer 2 (Data Link Layer) describes the logical organization of data bits transmitted on a particular medium. This layer defines the framing, addressing and checksumming of Ethernet packets. Layer 3 (Network Layer) describes how a series of exchanges over various data links can deliver data between any two nodes in a network. This layer defines the addressing and routing structure of the Internet. Utility describes commands used to manage the switch. Commands that cause specific actions to be taken immediately by the system and do not directly affect the system configurations are defined at the top of the command tree. For example, commands for rebooting the system or for downloading or backing up the system configuration files are placed at the top of the hierarchy tree. Commands that result in configuration changes to the switch are grouped in a Configuration sub tree. There are levels beneath the Configuration mode for further grouping of commands. The system prompt reflects these sub-Configuration modes. All the parameters are provided with reasonable defaults where possible. When starting a session, the initial mode is the User EXEC mode. Only a limited subset of commands is available in this mode. This level is reserved for tasks that do not change the configuration. To enter the next level, the Privileged EXEC mode, a password is required. Using the CLI 141