C-CiscoIOS简介.ppt

Slide 1 of 1 Purpose: Emphasize: Notice that there are more commands available on the router than the Cat 1900 switch. Slide 1 of 1 Purpose: Emphasize: Note: The Cat 1900 has a fixed history size of 10 which can’t be changed. Slide 1 of 1 Purpose: Emphasize: Suppose you want to set the router clock. If you do not know the command, use context-sensitive help to check the syntax for setting the clock. The help output shows that the set keyword is required. Next, check the syntax for entering the time. Now enter the current time using hours, minutes, and seconds, as shown. The system indicates that you need to provide additional arguments to complete the command. Press Ctrl-P (or Up arrow) to repeat the previous command entry automatically. Then add a space and a question mark (?) to reveal the additional arguments. Now you can complete the command entry. The caret symbol (^) and help response indicate an error. To list the correct syntax, reenter the command up to the point where the error occurred, and then enter a question mark (?). Enter the year using the correct syntax and press Return to execute the command. Note that the user interface provides syntax checking in the form of an error location indicator (^). The caret symbol character appears at the point in the command string where you have entered an incorrect command, keyword, or argument. The error location indicator and interactive help system allow you to find and correct syntax errors easily. Slide 2 of 9 Purpose: Emphasize: Layer 2—Here is the same line after it has started scrolling. Notice that a dollar sign ($) appears at the beginning of the line after the prompt. This special character indicates that more characters to the left are not shown. Slide 3 of 9 Purpose: Emphasize: Layer 3—The interface implements some sophisticated motion commands for working with the scrolled line. For example, if you want to see the beginning of the line, press Ctrl-A to place the cursor on the first charact