Chapter 2.1: Configuring a Network Operating System: IOS Bootcamp Flashcards
1
Q
What do all end devices and network devices need in order to help them perform their function on a network?
2.1.1.1
A
All end devices and network devices connected to the internet require an operating system to help them perform their function.
2
Q
What is a kernel?
2.1.1.1
A
It is the portion of the OS code that interacts directly with the computer hardware. It also manages how hardware resources are used to meet software requirements.
3
Q
What is a shell?
2.1.1.1
A
It is the portion of the OS code that interfaces with the applications and user. It allows users to request specific tasks from the computer through CLI or GUI interfaces.
4
Q
What are the two ways a user can interact with the shell?
2.1.1.1
A
They can interact with the shell using CLI or GUI
5
Q
What is CLI?
2.1.1.1
A
Command Line Interface
6
Q
What is GUI?
2.1.1.1
A
Graphical User Interface
7
Q
How does a CLI work?
2.1.1.1
A
A user interacts directly with the system in a text-based environment by entering commands on the keyboard at a command prompt.
The system then executes the command.
The system usually provides textual output.
(short version)
User enters commands on command prompt, System executes the command, system may provide textual output.
8
Q
How does a GUI work?
2.1.1.1
A
It allows the user to interact with the system in an environment that uses graphical images, multimedia, and text.
User interacts with images on a screen.
The system executes commands.
There is usually a graphical feedback.
9
Q
Why do people rely more on GUI’s?
2.1.1.1
A
GUI’s are user friendly and requires less knowledge of the command structure to utilize the system.
10
Q
Which shell do most end devices use for their operating system?
2.1.1.1
A
They usually use GUI interfaces. Examples include MS Windows, MAC OS X, Linux, Apple iOS, Android, and more.
11
Q
What is the operating system on most home routers called?
2.1.1.1
A
Firmware
12
Q
What is the most common method for configuring a home router?
2.1.1.1
A
Using a web browser as an easy to use GUI.
13
Q
What do Infrastructure network devices use in order to function?
A
They use a network operating system.
14
Q
What is the network operating system used on Cisco devices?
2.1.1.1
A
Cisco Internetwork Operating System (IOS). These are an array of different operating systems that run on various networking devices.
IOS for switches, routers, and other CISCO networking devices.
IOS numbered versions for a given CISCO networking device.
IOS feature sets providing distinct packages of features and services.
15
Q
What is the most common method (shell type) of accessing network devices?
2.1.1.1
A
Command Line Interface CLI
16
Q
What are some similarities between network operating systems and PC operating systems?
2.1.1.2
A
use “behind the scenes” technical functions that enable a user to
- use a mouse
- view output on a monitor
- enter text commands
- select options within a dialog box window
17
Q
Is it possible to upgrade Cisco IOS for a networking device?
2.1.1.2
A
Yes. This is similar to how there are different versions of operating systems.
18
Q
How big is IOS file and where is the IOS file stored?
2.1.1.3
A
It is several megabytes in size and is stored in a semi-permanent memory area called flash, a non-volatile storage area and can be changed or overwritten, if needed,
It allows the IOS to be upgraded with a new version or new features.
-It can store multiple versions of IOS software.
-Hardware does not need to be replaced in order to upgrade. (card)?
19
Q
What happens when most Cisco devices are turned on?
2.1.1.3
A
The IOS is copied from the flash into Random Access Memory and the IOS runs from the RAM when the device is operating.
20
Q
What function does RAM have for CISCO devices?
2.1.1.3
A
It runs the operating system
It stores data
21
Q
What is a power cycle?
2.1.1.3
A
When a device is purposely or accidentally powered off and them powered back on.
22
Q
Why is it important to determine the flash and RAM requirements for each device?
2.1.1.3
A
The quantity of flash memory and RAM memory required for a given IOS varies dramatically from device to device. Newer versions of IOS may demand more RAM and Flash than can be installed on some devices.
23
Q
What are the major functions performed or enabled by Cisco routers and switches?
2.1.1.4
A
-Providing Network Security
-IP addressing of virtual and physical interfaces
-Enabling interface-specific configurations to optimize connectivity of the respective media
Routing
-Enabling quality of service (QoS) technologies
Supporting network management technologies
Short
MASRIQ
Managing resources, Addressing, Security, Routing, Interface, QoS
24
Q
What does each feature or service in Cisco IOS have?
2.1.1.4
A
An associated collection of configuration commands that allow a network technician to implement it.
25
What is CCO?
| Import from 2.0
Cisco Connection Online
26
What are the three most common ways to access a Cisco CL environment?
2.1.2.1
Console
Tenet or SSH
Aux Port
27
What is console port?
| 2.1.2.1
Console port is a management port that provides out-of-band access to Cisco device.
28
What is out-of-band?
It refers to access via a dedicated management channel that is used for device maintenance purposes only.
29
What are the advantages of using a console port
The device is accessible even if no networking services have been configured. This is useful for the initial configuration and when networking services have failed and remote access of the Cisco IOS device is not possible.
30
How does a console port work?
A computer running terminal emulation software is connected to the console port of the device using a special cable.
The computer that is connected to the switch or router can enter commands for setting up the device.
31
What does the console convey by default and why is this important?
By default, the console conveys the device startup, debugging, and error messages. After the network technician is connected to the device, the network technician can perform any configuration commands necessary using the console session.
32
Do most IOS device console access require any form of security by default? How does one keep the device secure?
No they do not. However, the console should be configured with passwords to prevent unauthorized device access. In the event that a password is lost, there is a special set of procedures for bypassing the password and accessing the device. The device should also be located in a locked room or equipment rack to prevent unauthorized physical access.
33
What are two different methods for remotely establishing a CLI session of a network device?
2.1.2.2
Telnet and Secure Shell(SSH)
34
What is telnet?
A method for remotelyestablishing a CLI session of a device, through a virtual inteface, over a network. Unlike the console connection Telnet requires active networking services on the device. It must have at least one active interface configured with an internet address, such as an IPv4 address.
Cisco IOS devices include a Telnet server process that allows users to enter configuration commands from a Telnet client. In addition to supporting the Telnet server process, the Cisco IOS device also contains a Telnet client. This allows a network administrator to telnet from the Cisco device CLI to any other device that supports a Telnet server process
35
What is SSH?
The Secure Shell protocol provides a remote login that is more secure than Telnet.
36
How is SSH more secure than Telnet?
They provide stronger password authentication than Telnet and use encryption when transporting session data. This keeps the user ID, password, and the details of the management session private.
37
Whenever possible which should an adminstrator use for remote access to a Cisco device, Telnet or SSH?
Administrators should use SSH whenever possible because it is more secure than Telnet.
38
What is an AUX port?
Auxiliary (AUX) port to a router is an older way to establish a CLI session remotely via a telephone dialup connection. It is also an out of band connection and does not require any networking services to be configured or available on the device.
In the event that network services have failed, it may be possible for a remote administrator to access the switch or router over a telephone line.
The AUX port can also be used locally, though console port is preferred over AUX port for troubleshooting because the console port displays start up, debugging and error messages by default.
39
Which switch does not support AUX port?
Cisco Catalyst switches do not.
40
Which port is preferred locally and why?
the console port is preferred over the AUX port for troubleshooting because it displays startup, debugging, and error messages by default.
41
List Terminal Emulation programs for console port or Telnet/SSH.
2.1.2.3
```
PuTTY (Figure 1)
Tera Term (Figure 2)
SecureCRT (Figure 3)
HyperTerminal
OS X Terminal
```
These programs allow you to enhance your productivity by adjusting window sizes, changing font sizes, and changing color schemes.
42
What structure does a Cisco IOS CLI use?
| 2.1.3.1
It uses a heirarchical structure for the modes.
Each mode has a distinctive prompt and is used to accomplish particular tasks with a specific set of commands that are available only to that mode.
43
What are the major IOS modes from most basic to most specialized?
- User executive (User EXEC) mode
- Privileged executive (Privileged EXEC) mode
- Global configuration mode (the device as whole including naming the device)
- Other specific configuration modes, such as interface configuration mode
44
How can a heirarchical structure be configured to provide security
Different authentication can be required for each hierarchical mode. This controls the level of access that network personnel can be granted.
45
What are the two primary modes of operation for an IOS?
| 2.1.3.2
User EXEC mode and Privileged EXEC Mode
46
What is the User EXEC mode?
It is the most basic level of the modal hierarchical structure
- It is the first mode encountered upon entrance into the CLI of an IOS device.
- Allows only a limited number of basic monitoring commands. Referred to as "view only"
47
What are the limitations of user EXEC mode?
- Monitoring only
| - cannot execute commands that might change the configuration of the device.
48
True or False: the user EXEC mode from the console has user authentication as the default.
False. However, it is a good practice to ensure that authentication is configured during the initial configuration.
49
How is the user EXEC mode identified by the CLI prompt?
A prompt that ends in >
ex.
Switch>
Router>
50
What is Privileged EXEC mode?
A mode that allows the execution of configuration and management commands.
51
How does a user enter into privileged EXEC mode?
First users must enter into user EXEC mode.
52
How is the privileged EXEC mode identified by the CLI prompt?
A prompt that ends in #
ex
Switch#
Router#
53
True or False: The privileged EXEC mode requires authentication?
False. It is a good practice to ensure that authentication is configured.
54
What mode is the gateway to Global Configuration mode and Specific configuration modes?
Privileged EXEC mode
55
What is global configuration mode?
| 2.1.3.3
It is the primary configuration mode. In this mode CLI configuration changes are made that affect the operation of the device as a whole.
56
How does a user enter global configuration mode?
The user enters user EXEC mode, privileged mode, and then enters into Global Configuration mode.
57
How is the Global Configuration mode identified by the CLI prompt?
A prompt that ends in (config)#
| Switch (config)#
58
How does a user transition from privileged EXEC mode to Global configuration mode?
configure terminal
59
What are Specific Configuration modes?
sub-configuration modes in the global configuration mode that allows the configuration of a particular part or function of the IOS device.
60
List a few Specific Configuration modes.
Interface mode-to configure one of the network interfaces.
| Line mode - to configure one of the physical or virtual lines.
61
How do you exit specific configuration mode and return to global configuration mode?
Enter "exit" at the prompt.
62
How do you leave configuration mode completely and return to privileged EXEC mode?
Enter "end" or key sequence Ctrl-Z
63
How is the Specific Configuration mode identified by the CLI prompt?
Identifies the specific configuration mode after config-
(interface mode)
Switch (config-if)#
64
What is the structure for the Command-Line prompt?
Device Mode
Switch>
(Device: switch, Mode: user EXEC)
Router#
(Device: router, Mode: privileged EXEC)
Switch (config)#
(Device: switch, Mode: Global Configuration)
Router (config-if)#
(Device: router, Mode: Interface Configuration)
65
Which commands are used to change the CLI between user exec mode and the privileged EXEC mode?
2.1.3.4
enable and disable are used to switch modes.
In user EXEC mode type enable and it will switch to privileged EXEC mode or prompt for a password if authentication is required. To return to user EXEC mode, type "disable"
```
EX.
Switch>
Switch> enable
Password:
Switch #
Switch # disable
Switch >
```
66
In each mode, what does the command "exit" do?
| 2.1.3.5
user EXEC - ends a console session to login screen
privileged EXEC - ends a console session to login screen
global configuration - goes to privileged EXEC mode
specific configuration - goes to global configuration mode
67
From global configuration mode how do you enter a specific configuration mode?
Enter command for the specific configuration mode.
Switch (config) #
Switch (config) # line vty 0 4
Switch (config-line) #
68
how do you move from a sub-mode of global configuration to another "immediate" sub-mode of the global configuration mode.
enter the corresponding command as you would for the global configuration mode.
Switch (config-line)# interface fastethernet 0/1
Switch (config-if)#
69
In each mode what does the command "end" (or Ctrl-Z) do? "
| ?
user EXEC mode -
privileged EXEC mode - moves to user EXEC mode.
global configuration mode -
specific configuration mode - moves to privileged EXEC mode
70
What is the general syntax for a command con a Cisco OSI?
| 2.1.4.1
Prompt : Command : (physical space) : Keyword or Argument
Ex
Switch>ping 193.168.10.5
Switch>show ip protocols
71
Can all commands be executed in any mode? why or why not?
No. Each command has a specific format and syntax and can only be executed at the appropriate mode.
Commands include a set of keywords and arguments.
72
What are commands used for?
They are used to execute an action.
73
What are keywords used for?
They are used to identify where or how to execute the command.
74
Are commands case sensitive?
No.
75
What follows a command?
One or more keywords.
76
What must a user do to enter a complete command?
write a command and a keyword or argument and then press enter.
77
What do keywords do?
They describe specific parameters to the command interpreter.
78
What is an argument?
An argument is a value or variable defined by the user that follows the command syntax
79
What is a command syntax?
a pattern or format that must be used when entering a command.
80
In the IOS command structure, what does boldface text mean?
It indicates commands and keywords that are typed as shown.
81
In the IOS command structure, what does Italic text mean?
It indicates an argument for which you supply a value.
82
In the IOS command structure, what do brackets [ ] mean?
It indicates an optional element (keyword or argument).
83
In the IOS command structure, what do braces { } mean?
They group required choices while vertical bars (|) separate the alternative elements.
84
In the IOS command structure, what do braces and vertical lines within square brackets [{|}] mean?
It means a required choice within an optional element.
85
What is The Cisco IOS Command Reference?
| 2.1.4.2
a collection of online documentation which describes in detail the IOS commands used on Cisco devices. The Command Reference is the ultimate source of information for a particular IOS command, similar to how a dictionary is the ultimate source for information about a particular word.
86
What are common characteristics of IOS commands?
- Syntax - the most detailed version of the syntax for a command that can be found
- Default - the manner in which the command is implemented on a device with a default configuration
- Mode - the configuration mode on the device where the command is entered
- History - descriptions of how the command is implemented relative to the IOS version
- Usage Guidelines - guidelines describing specifically how to implement the command
- Examples - useful examples that illustrate common scenarios that use the command
87
What are three forms of help available in the IOS?
| 2.1.4.3
Context-Sensitive Help
Command Syntax Check
Hot Keys and Shortcuts
88
What is context sensitive help?
it helps provide a list of commands, the arguments associated with those commands
89
how do you get context sensitive help?
type the ? at any prompt
90
How do you get context sensitive help to find all available commands that start with the letter c
type c? at any prompt
91
How do you use context sensitive help to determine which options, keywords or arguments are matched with a specific command?
When entering a command, enter a space followed by a ? to determine what can or should be entered next.
92
How dos command syntax check work?
| 2.1.4.4
When a command is submitted by pressing the Enter key, the command line interpreter parses the command from left to right to determine what action is being requested. The IOS generally only provides negative feedback, as shown in Figure 1. If the interpreter understands the command, the requested action is executed and the CLI returns to the appropriate prompt. However, if the interpreter cannot understand the command being entered, it will provide feedback describing what is wrong with the command.
93
What are three different types of error messages for command syntax check and what do they mean?
- Ambiguous command - Not enough characters were entered for the IOS to recognize the command
- Incomplete command - not all of the required keywords or arguments were entered
- Incorrect command - the command was entered incorrectly the error appears where the caret mark (^) appears
(look at figure 2 to find how to get help from the context sensitive help)
94
What are the major CL hot keys and shortcuts?
| 2.1.4.5
(redo)
Down Arrow - Allows the user to scroll forward through former commands
Up Arrow - Allows the user to scroll backward through former commands
Tab - Completes the remainder of a partially typed command or keyword
Ctrl-A - Moves to the beginning of the line
Ctrl-E - Moves to the end of the line
Ctrl-R - Redisplays a line
Ctrl-Z - Exits the configuration mode and returns to privileged EXEC mode
Ctrl-C - Exits the configuration mode or aborts the current command
Ctrl-Shift-6 - Allows the user to interrupt an IOS process such as ping or traceroute
Examining some of these in more detail:
Tab
Tab complete is used to complete the remainder of abbreviated commands and parameters if the abbreviation contains enough letters to be different from any other currently available commands or parameters. When enough of the command or keyword has been entered to appear unique, press the Tab key and the CLI will display the rest of the command or keyword.
This is a good technique to use when you are learning because it allows you to see the full word used for the command or keyword.
Ctrl-R
Redisplay the line will refresh the line just typed. Use Ctrl-R to redisplay the line. For example, you may find that the IOS is returning a message to the CLI just as you are typing a line. You can use Ctrl-R to refresh the line and avoid having to retype it.
In this example, a message regarding a failed interface is returned in the middle of a command.
Switch# show mac-
16w4d: %LINK-5-CHANGED: Interface FastEthernet0/10, changed state to down
16w4d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/10, changed state to down
To redisplay to line that you were typing use Ctrl-R:
Switch# show mac
Ctrl-Z
Exit configuration mode will leave any configuration mode and return to privileged EXEC mode. Because the IOS has a hierarchical mode structure, you may find yourself several levels down. Rather than exit each mode individually, use Ctrl-Z to return directly to the privileged EXEC prompt at the top level.
Up and Down Arrows
Previous command keys will recall the history of commands entered. The Cisco IOS software buffers several past commands and characters so that entries can be recalled. The buffer is useful for re-entering commands without retyping.
Key sequences are available to scroll through these buffered commands. Use the Up Arrow key (Ctrl-P) to display the previously entered commands. Each time this key is pressed, the next successively older command will be displayed. Use the Down Arrow key (Ctrl-N) to scroll forward through the history to display the more recent commands.
Ctrl-Shift-6
The escape sequence will interrupt any running process. When an IOS process is initiated from the CLI, such as a ping or traceroute, the command runs until it is complete or is interrupted. While the process is running, the CLI is unresponsive. To interrupt the output and interact with the CLI, press Ctrl-Shift-6.
Ctrl-C
This interrupts the entry of a command and exits the configuration mode. This is useful after entering a command that needs to be cancelled.
95
What are the major hot keys at the ----More----- prompt?
Enter key - Displays the next line
Space Bar - Displays the next screen
Any other key - ends the display string, returning to privileged EXEC mode.
96
What are the Break keys in IOS?
Ctrl-C -While in any configuration mode, ends the configuration mode and returns to privileged EXEC mode. When in setup mode, aborts back to the command prompt.
Ctrl-Z While in any configuration mode, ends the configuration mode and returns to privileged EXEC mode.
Ctrl-Shift-6 - All purpose break sequence. Use to abort DNS lookups, traceroutes, pings.
97
How do abbreviated commands or Keywords work?
Commands and keywords can be abbreviated to the minimum number of characters that identify a unique selection. For example, the configure command can be abbreviated to conf because configure is the only command that begins with conf. An abbreviation of con will not work because more than one command begins with con.
98
What is the basic examination command?
| 2.1.4.6
show
99
what does show ? do?
retrieves a list of available commands in a given context or mode.
100
what does a typical show command provide?
information about the configuration, operation, and status of parts of a Cisco switch or router.
101
What does the command show interface do?
It displays statistics for all interfaces on the device
102
How do you view the statistics for a specific interface?
Rnter the show interfaces command followed by the specific interface type and slot/port number. For example:
Switch# show interfaces fastethernet 0/1
103
What does the command show startup-config show?
Displays the saved configuration located in NVRAM.
104
What does the command show running-config show?
Displays the contents of the currently running configuration file.
105
What is some information show version displays?
Software version - IOS software version (stored in flash)
Bootstrap version - Bootstrap version (stored in Boot ROM)
System up-time - Time since last reboot
System restart info - Method of restart (e.g., power cycle, crash)
Software image name - IOS filename stored in flash
Router type and processor type - Model number and processor type
Memory type and allocation (shared/main) - Main Processor
RAM and Shared Packet I/O buffering
Software features - Supported protocols/feature sets
Hardware interfaces - Interfaces available on the device
Configuration register - Sets bootup specifications, console speed setting, and related parameters
106
Labs
Activities: 2.1.2.4
| Labs : 2.1.4.8, 2.1.4.9
