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Table Of Contents
Using the No and Default Forms of Commands
Accessing the MSFC CLI from the Supervisor Engine CLI
Cisco IOS Command-Line Interface
Command-Line Interface
This chapter provides information for understanding and using the Catalyst 6500 series switch Cisco IOS software using the command-line interface (CLI). This chapter includes the following sections:
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MSFC CLI
For an overview of the Catalyst 6500 series switch Cisco IOS software configuration, refer to the Catalyst 6500 Series IOS Software Configuration Guide.
Getting Help
To obtain a list of commands that are available for each command mode, enter a question mark (?) at the system prompt. You also can obtain a list of any command's associated keywords and arguments with the context-sensitive help feature.
Table 1-1 lists commands you can enter to get help that is specific to a command mode, a command, a keyword, or an argument.
How to Find Command Options
This section provides an example of how to display syntax for a command. The syntax can consist of optional or required keywords. To display keywords for a command, enter a question mark (?) at the configuration prompt or after entering part of a command followed by a space. The Catalyst 6500 series switch software displays a list of available keywords along with a brief description of the keywords. For example, if you are in global configuration mode and want to see all the keywords for the arap command, you enter arap ?.
Table 1-2 shows examples of how you can use the question mark (?) to assist you in entering commands and also guides you through entering the following commands:
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Using the No and Default Forms of Commands
Almost every configuration command has a no form. In general, enter the no form to disable a function. Use the command without the keyword no to reenable a disabled function or to enable a function that is disabled by default. For example, IP routing is enabled by default. To disable IP routing, specify the no ip routing command and specify ip routing to reenable it. This publication provides the complete syntax for the configuration commands and describes what the no form of a command does.
Configuration commands can have a default form. The default form of a command returns the command setting to its default. Most commands are disabled by default, so the default form is the same as the no form. However, some commands are enabled by default and have variables set to certain default values. In these cases, the default form of the command enables the command and sets variables to their default values. This publication describes what the default form of a command does if the command is not the same as the no form.
Using the CLI String Search
The pattern in the command output is referred to as a string. The CLI string search feature allows you to search or filter any show or more command output and allows you to search and filter at --More-- prompts. This feature is useful when you need to sort though large amounts of output, or if you want to exclude output that you do not need to see.
With the search function, you can begin unfiltered output at the first line that contains a regular expression you specify. You can then specify a maximum of one filter per command or start a new search from the --More-- prompt.
A regular expression is a pattern (a phrase, number, or more complex pattern) software uses to match against show or more command output. Regular expressions are case sensitive and allow for complex matching requirements. Examples of simple regular expressions are Serial, misses, and 138. Examples of complex regular expressions are 00210..., ( is ), and [Oo]utput.
You can perform three types of filtering:
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You can then search this filtered output at the --More-- prompts.
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Regular Expressions
A regular expression can be a single character that matches the same single character in the command output or multiple characters that match the same multiple characters in the command output. This section describes how to create both single-character patterns and multiple-character patterns and how to create more complex regular expressions using multipliers, alternation, anchoring, and parentheses.
Single-Character Patterns
The simplest regular expression is a single character that matches the same single character in the command output. You can use any letter (A-Z, a-z) or digit (0-9) as a single-character pattern. You can also use other keyboard characters (such as ! or ~) as single-character patterns, but certain keyboard characters have special meaning when used in regular expressions. Table 1-3 lists the keyboard characters with special meaning.
To enter these special characters as single-character patterns, remove the special meaning by preceding each character with a backslash (\). These examples are single-character patterns matching a dollar sign, an underscore, and a plus sign, respectively.
\$ \_ \+
You can specify a range of single-character patterns to match against command output. For example, you can create a regular expression that matches a string containing one of the following letters: a, e, i, o, or u. One and only one of these characters must exist in the string for pattern matching to succeed. To specify a range of single-character patterns, enclose the single-character patterns in square brackets ([ ]). For example,
[aeiou]
matches any one of the five vowels of the lowercase alphabet, while
[abcdABCD]
matches any one of the first four letters of the lower- or uppercase alphabet.
You can simplify ranges by entering only the end points of the range separated by a dash (-). Simplify the previous range as follows:
[a-dA-D]
To add a dash as a single-character pattern in your range, include another dash and precede it with a backslash:
[a-dA-D\-]
You can also include a right square bracket (]) as a single-character pattern in your range. To do so, enter the following:
[a-dA-D\-\]]
The previous example matches any one of the first four letters of the lower- or uppercase alphabet, a dash, or a right square bracket.
You can reverse the matching of the range by including a caret (^) at the start of the range. This example matches any letter except the ones listed:
[^a-dqsv]
This example matches anything except a right square bracket (]) or the letter d:
[^\]d]
Multiple-Character Patterns
When creating regular expressions, you can also specify a pattern containing multiple characters. You create multiple-character regular expressions by joining letters, digits, or keyboard characters that do not have special meaning. For example, a4% is a multiple-character regular expression. Put a backslash in front of the keyboard characters that have special meaning when you want to remove their special meaning.
With multiple-character patterns, order is important. The regular expression a4% matches the character a followed by a 4 followed by a % sign. If the string does not have a4%, in that order, pattern matching fails. This multiple-character regular expression
a.
uses the special meaning of the period character to match the letter a followed by any single character. With this example, the strings ab, a!, or a2 are all valid matches for the regular expression.
You can remove the special meaning of the period character by putting a backslash in front of it. In the following expression
a\.
only the string a. matches this regular expression.
You can create a multiple-character regular expression containing all letters, all digits, all keyboard characters, or a combination of letters, digits, and other keyboard characters. These examples are all valid regular expressions:
telebit 3107 v32bis
Multipliers
You can create more complex regular expressions to match multiple occurrences of a specified regular expression by using some special characters with your single- and multiple-character patterns. Table 1-4 lists the special characters that specify "multiples" of a regular expression.
This example matches any number of occurrences of the letter a, including none:
a*
This pattern requires that at least one letter a in the string is matched:
a+
This pattern matches the string bb or bab:
ba?b
This string matches any number of asterisks (*):
\**
To use multipliers with multiple-character patterns, you enclose the pattern in parentheses. In the following example, the pattern matches any number of the multiple-character string ab:
(ab)*
As a more complex example, this pattern matches one or more instances of alphanumeric pairs (but not none; that is, an empty string is not a match):
([A-Za-z][0-9])+
The order for matches using multipliers (*, +, or ?) is to put the longest construct first. Nested constructs are matched from outside to inside. Concatenated constructs are matched beginning at the left side of the construct. Thus, the regular expression matches A9b3, but not 9Ab3 because the letters are specified before the numbers.
Alternation
Alternation allows you to specify alternative patterns to match against a string. You separate the alternative patterns with a vertical bar (|). Exactly one of the alternatives can match the string. For example, the regular expression
codex | telebit
matches the string codex or the string telebit, but not both codex and telebit.
Anchoring
You can match a regular expression pattern against the beginning or the end of the string. That is, you can specify that the beginning or end of a string contains a specific pattern. You "anchor" these regular expressions to a portion of the string using the special characters shown in Table 1-5.
Table 1-5 Special Characters Used for Anchoring
^
Matches the beginning of the string.
$
Matches the end of the string.
This regular expression matches a string only if the string starts with abcd:
^abcd
In contrast, this expression is in a range that matches any single letter, as long as it is not the letters a, b, c, or d:
[^abcd]
With this example, the regular expression matches a string that ends with .12:
$\.12
Contrast these anchoring characters with the special character underscore (_). The underscore matches the beginning of a string (^), the end of a string ($), parentheses ( ), space ( ), braces { }, comma (,), or underscore (_). With the underscore character, you can specify that a pattern exist anywhere in the string.
For example:
_1300_
matches any string that has 1300 somewhere in the string. The string's 1300 can be preceded by or end with a space, brace, comma, or underscore. For example:
{1300_
matches the regular expression, but 21300 and 13000 do not.
Using the underscore character, you can replace long regular expression lists, such as the following:
^1300$ ^1300(space) (space)1300 {1300, ,1300, {1300} ,1300, (1300
with
_1300_
Parentheses for Recall
As shown in the "Multipliers" section, you use parentheses with multiple-character regular expressions to multiply the occurrence of a pattern. You can also use parentheses around a single- or multiple-character pattern to remember a pattern for use elsewhere in the regular expression.
To create a regular expression that recalls a previous pattern, you use parentheses to indicate a remembered specific pattern and a backslash (\) followed by an integer to reuse the remembered pattern. The integer specifies the occurrence of the parentheses in the regular expression pattern. If you have more than one remembered pattern in your regular expression, then \1 indicates the first remembered pattern, \2 indicates the second remembered pattern, and so on.
This regular expression uses parentheses for recall:
a(.)bc(.)\1\2
This regular expression matches an a followed by any character (call it character 1), followed by bc followed by any character (character 2), followed by character 1 again, followed by character 2 again. The regular expression can match aZbcTZT. The software remembers that character 1 is Z and character 2 is T and then uses Z and T again later in the regular expression.
alt Keyword Usage
When you enable high-availability redundancy, every configuration command executed on the designated MSFC is sent to the nondesignated MSFC. Also, the running configuration synchronization is updated when you enter the copy source running-config command on the designated MSFC.
The two states for the configuration synchronization are as follows:
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To configure both MSFCs from a single console, enter the alt keyword to specify an alternate configuration. When specifying the alternate configuration, the configuration that is specified before the alt keyword relates to the MSFC on the supervisor engine in slot 1 of the switch; the configuration that is specified after the alt keyword relates to the MSFC on the supervisor engine in slot 2.
Note
When you enable the Config Sync RuntimeStatus, the following occurs:
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When the Config Sync RuntimeStatus is in disabled mode, the following occurs:
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Table 1-6 shows the interface and global configuration commands that contain the alt keyword:
This example shows how the alt keyword is used when entering the ip address command:
Router-1(config-if)# ip address 1.2.3.4 255.255.255.0 alt ip address 1.2.3.5 255.255.255.0Saving Configuration Changes
To save your configuration changes to your startup configuration so that they will not be lost if there is a system reload or power outage, enter the following command:
Router# copy system:running-config nvram:startup-configBuilding configuration...It might take a minute or two to save the configuration. After the configuration has been saved, the following output appears:
[OK]Router#On most platforms, this step saves the configuration to NVRAM. On the Class A Flash file system platforms, this step saves the configuration to the location specified by the CONFIG_FILE environment variable. The CONFIG_FILE environment variable defaults to NVRAM.
MSFC CLI
You can access the Multilayer Switch Feature Card (MSFC) command-line interface (CLI) by entering commands from the supervisor engine CLI. These sections describe the MSFC CLI:
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Accessing the MSFC CLI from the Supervisor Engine CLI
These sections describe how to access the MSFC CLI from a directly connected console port or from a Telnet session:
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Accessing the MSFC CLI from the Console Port
You can enter the switch console command to access the MSFC CLI from the supervisor engine CLI directly connected to the console port. To exit from the MSFC CLI and return to the supervisor engine CLI, enter ^C^C^C at the Router> prompt.
To access the MSFC CLI from the supervisor engine CLI, perform this task:
Access the MSFC CLI from the supervisor engine CLI.
switch console [mod]1
1 The mod variable specifies the module number of the MSFC; either 15 (if the MSFC is installed on the supervisor engine in slot 1) or 16 (if the MSFC is installed on the supervisor engine in slot 2). If no module number is specified, the console will switch to the MSFC on the active supervisor engine.
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This example shows how to access the active MSFC CLI from the active supervisor engine CLI, and how to exit the MSFC CLI and return to the supervisor engine CLI:
Console> (enable) switch console 15Trying Router-15...Connected to Router-15.Type ^C^C^C to switch back...Router>^C^C^CConsole> (enable)Accessing the MSFC CLI from a Telnet Session
You can enter the session mod command to access the MSFC CLI from the supervisor engine CLI using a Telnet session. To exit from the MSFC CLI back to the supervisor engine CLI, enter the exit command at the Router> prompt.
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This example shows how to access the MSFC from the supervisor engine CLI, and how to exit the MSFC CLI and return to the supervisor engine CLI:
Console> (enable) session 15Router> exitConsole> (enable)
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http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/secur_c/scprt1/scdathen.htmCisco IOS Command Modes
The Cisco IOS user interface is divided into many different modes. The commands available to you depend on which mode you are currently in. To get a list of the commands in a given mode, type a question mark (?) at the system prompt. For more information, see the "Getting a List of Cisco IOS Commands and Syntax" section on page 2-14.
When you start a session on the supervisor engine, you begin in user mode, often called user EXEC mode. Only a limited subset of the commands are available in EXEC mode. To have access to all commands, you must enter privileged EXEC mode. Normally, you must type in a password to access privileged EXEC mode. From privileged EXEC mode, you can type in any EXEC command or access global configuration mode. Most of the EXEC commands are one-time commands, such as show commands, which show the current configuration status, and clear commands, which clear counters or interfaces. The EXEC commands are not saved across reboots of the supervisor engine.
The configuration modes allow you to make changes to the running configuration. If you later save the configuration, these commands are stored across supervisor engine reboots. You must start at global configuration mode. From global configuration mode, you can enter interface configuration mode, subinterface configuration mode, and a variety of protocol-specific modes.
ROM monitor mode is a separate mode used when the supervisor engine cannot boot properly. For example, the supervisor engine might enter ROM monitor mode if it does not find a valid system image when it is booting, or if its configuration file is corrupted at startup. For more information, see the "Catalyst 6500 Series IOS Command Reference."
Table 1-7 lists and describes the most commonly used Cisco IOS modes.
The Cisco IOS command interpreter, called the EXEC, interprets and executes the commands that you enter. You can abbreviate commands and keywords by entering just enough characters to make the command unique from other commands. For example, you can abbreviate the show command to sh and the configure terminal command to config t.
When you type exit, the MSFC backs out one level. To exit configuration mode completely and return to privileged EXEC mode, press Ctrl-Z.
Getting a List of Cisco IOS Commands and Syntax
In any command mode, you can get a list of available commands by entering a question mark (?).
Router> ?To obtain a list of commands that begin with a particular character sequence, type in those characters followed by the question mark (?). Do not include a space. This form of help is called word help, because it completes a word for you.
Router# co?configureTo list keywords or arguments, enter a question mark in place of a keyword or argument. Include a space before the question mark. This form of help is called command syntax help, because it reminds you which keywords or arguments are applicable based on the command, keywords, and arguments you have already entered.
Router# configure ?memory Configure from NV memorynetwork Configure from a TFTP network hostoverwrite-network Overwrite NV memory from TFTP network hostterminal Configure from the terminalTo redisplay a command you previously entered, press the up-arrow key or Ctrl-P. You can continue to press the up-arrow key to see the last 20 commands that you entered.
Tips
Press Ctrl-Z in any mode to immediately return to privileged EXEC mode. Enter exit to return to the previous mode.
Cisco IOS Command-Line Interface
These sections describe basic Cisco IOS configuration tasks that you need to understand before you configure routing:
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Accessing Cisco IOS Configuration Mode
To access the Cisco IOS configuration mode, perform this task:
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Viewing and Saving the Cisco IOS Configuration
To view and save the configuration after you make changes, perform this task:
Bringing Up an MSFC Interface
In some cases, an MSFC interface might be administratively shut down. You can check the status of an interface using the show interface command.
Note
To bring up an MSFC interface that is administratively shut down, perform this task in privileged mode:
Posted: Fri May 20 15:10:18 PDT 2005
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