Cisco CCNA 1 questions Chapter 2

Global Configuration Mode

changes made affect the operation of the device as a whole accessed by entering the configure terminal command Symbol - Switch(config)#.

Save the Running Configuration File

copy running-config startup-config privileged EXEC mode command. alternatively copy run start will also save the running configuration file.

what are the three types of network media?

twisted-pair copper cables, fiber-optic cables, coaxial cables, or wireless

Primary Command Modes

• User EXEC Mode • Privileged EXEC Mode

Basic IOS Command Structure

A Cisco IOS device supports many commands. Each IOS command has a specific format or syntax and can only be executed in the appropriate mode. The general syntax for a command is the command followed by any appropriate keywords and arguments. Keyword - a specific parameter defined in the operating system (in the figure, ip protocols) Argument - not predefined; a value or variable defined by the user (in the figure, 192.168.10.5) After entering each complete command, including any keywords and arguments, press the Enter key to submit the command to the command interpreter.

IOS Command Syntax

A command might require one or more arguments. To determine the keywords and arguments required for a command, refer to the command syntax. The syntax provides the pattern or format that must be used when entering a command. As identified in the table in the figure, boldface text indicates commands and keywords that are entered as shown. Italic text indicates an argument for which the user provides the value. For instance, the syntax for using the description command is description string. The argument is a string value provided by the user. The description command is typically used to identify the purpose of an interface. For example, entering the command, description Connects to the main headquarter office switch, describes where the other device is at the end of the connection. The following examples demonstrate conventions used to document and use IOS commands. ping ip-address - The command is ping and the user-defined argument is the ip-address of the destination device. For example, ping 10.10.10.5. traceroute ip-address - The command is traceroute and the user-defined argument is the ip-address of the destination device. For example, traceroute 192.168.254.254. The Cisco IOS Command Reference is the ultimate source of information for a particular IOS command.

how many bits does a ipv4 subnet mask have?

An IPv4 subnet mask is a 32-bit value that separates the network portion of the address from the host portion.

What is a characteristic of a switch virtual interface SVI?

A switch virtual interface (SVI) represents a VLAN of switch ports as one interface to the routing or bridging function in the system. Only one SVI can be associated with a VLAN, but you need to configure an SVI for a VLAN only when you wish to route between VLANs or to provide IP host connectivity to the switch.

you call your manager to tell him you can't access you cannot access your router in another city over the internet. he provides with the information to access the router over the phone connection.

AUX

What are switch virtual interfaces (SVIs)?

Cisco IOS Layer 2 switches have physical ports for devices to connect. These ports do not support Layer 3 IP addresses. Therefore, switches have one or more switch virtual interfaces (SVIs). These are virtual interfaces because there is no physical hardware on the device associated with it. An SVI is created in software. The virtual interface provides a means to remotely manage a switch over a network using IPv4. Each switch comes with one SVI appearing in the default configuration "out-of-the-box." The default SVI is interface VLAN1. Note: A Layer 2 switch does not need an IP address. The IP address assigned to the SVI is used to remotely access the switch. An IP address is not necessary for the switch to perform its operations.

Syntax Checker - Configuring a Switch Virtual Interface

Configure a Switch Virtual Interface Enter interface configuration mode for VLAN 1. Configure the IPv4 address as 192.168.10.2 and the subnet mask as 255.255.255.0. Enable the interface. Switch(config)# interface vlan 1 Switch(config-if)# ip address 192.168.10.2 255.255.255.0 Switch(config-if)# no shutdown %LINK-5-CHANGED: Interface Vlan1, changed state to up Switch(config-if)# You have successfully configured the switch virtual interface for VLAN 1.

you are in equipment room with a new switch what needs to be configured?

Console

your manager gives you a special cable and tells you to configure the switch.

Console

Access Methods

Console - This is a physical management port that provides out-of-band access to a Cisco device. Out-of-band access refers to access via a dedicated management channel that is used for device maintenance purposes only. Secure Shell (SSH) - SSH is a method for remotely establishing a secure CLI connection through a virtual interface, over a network. Unlike a console connection, SSH connections require active networking services on the device including an active interface configured with an address. Telnet - Telnet is an insecure method of remotely establishing a CLI session through a virtual interface, over a network. Unlike SSH, Telnet does not provide a securely encrypted connection. User authentication, passwords, and commands are sent over the network in plaintext.

How to Configure Hostnames

Device Names Hostnames allow devices to be identified by network administrators over a network or the Internet. Very important and should also be displayed in the topology. Configure Hostnames IOS hostnames should: Start with a letter Contain no spaces End with letter or digit Use only letters, digits or dashes Be less than 64 characters in length switch# configure terminal switch(config)# hostname Sw-Floor-1 Sw-Floor-1(config)# Sw-Floor-1# configure terminal Sw-Floor-1(config)# no hostname switch(config)#

How do you enable routing on a layer 3 switch?

Enable routing on the switch with the ip routing command. ... Switch(config)#ip routing Make note of the VLANs that you want to route between. ... Use the show vlan command in order to verify that the VLANs exist in the VLAN database. ... Switch#vlan database Switch(vlan)#vlan 2 VLAN 2 added: Name: VLAN0002 Switch(vlan)#vlan 3 VLAN 3 added: Name: VLAN0003 Switch(vlan)#vlan 10 VLAN 10 added: Name: VLAN0010 Switch(vlan)#exit APPLY completed. Exiting.... Determine the IP addresses you want to assign to the VLAN interface on the switch. Configure the VLAN interfaces with the IP address identified in step 4. Switch#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface Vlan2 Switch(config-if)#ip address 10.1.2.1 255.255.255.0 Switch(config-if)#no shutdown Repeat this process for all VLANs identified in step 1. Configure the interface to the default router. In this scenario you have a Layer 3 FastEthernet port. Switch(config)#interface FastEthernet 0/1 Switch(config-if)#no switchport Switch(config-if)#ip address 200.1.1.1 255.255.255.0 Switch(config-if)#no shutdown The no switchport command makes the interface Layer 3 capable. The IP address is in the same subnet as the default router. Configure the default route for the switch. Switch(config)#ip route 0.0.0.0 0.0.0.0 200.1.1.2 From the diagram in the Task section, note that the IP address of the default router is 200.1.1.2. If the switch receives a packet for a network not in the routing table, it forwards it to the default gateway for further processing. From the switch, verify that you can ping the default router. Configure your end devices to use the respective Catalyst 3550 VLAN interface as their default gateway. For example, devices in VLAN 2 should use the interface VLAN 2 IP address as its default gateway. Refer to the appropriate client configuration guide for more information on how to designate the default gateway. (Optional) When you implement Inter-VLAN routing, you can also isolate some VLANs from being routed. Refer to the Isolation Between Two Layer 3 VLANs section of Creating Ethernet VLANs on Catalyst Switches for more information. Verify This section provides information in order to confirm that your configuration works properly. show ip route - Provides a snapshot of the routing table entries. Cat3550#show ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area, * - candidate default, U - per-user static route, o - ODR, P - periodic downloaded static route Gateway of last resort is 200.1.1.2 to network 0.0.0.0 200.1.1.0/30 is subnetted, 1 subnets C 200.1.1.0 is directly connected, FastEthernet0/48 10.0.0.0/24 is subnetted, 3 subnets C 10.1.10.0 is directly connected, Vlan10 C 10.1.3.0 is directly connected, Vlan3 C 10.1.2.0 is directly connected, Vlan2 S* 0.0.0.0/0 [1/0] via 200.1.1.2 Note that the routing table has an entry for each VLAN interface subnet. Therefore, devices in VLAN 3 can communicate with devices in VLAN 10, VLAN 2 and vice versa. The default route with the next hop 200.1.1.2 allows the switch to forward traffic to the gateway of last resort (for traffic the switch cannot route). show ip interface brief - Lists a brief summary of an interface's IP information and status. This command is used to verify that the VLAN interfaces and ports on the switch are up/up.

how to Encrypt Passwords

Enter the command to encrypt the plaintext passwords. Switch(config)# service password-encryption Exit global configuration mode and view the running configuration. Switch(config)# exit Use the show running-config command to verify that passwords are now encrypted.

hpw to Manual IP Address Configuration for End Devices

For an end device to communicate over the network, it must be configured with a unique IPv4 address and subnet mask. IP address information can be entered into end devices manually, or automatically using Dynamic Host Configuration Protocol (DHCP). To manually configure an IPv4 address on a Windows host, open the Control Panel > Network Sharing Center > Change adapter settings and choose the adapter. Next right-click and select Properties to display the Local Area Connection Properties. Highlight Internet Protocol Version 4 (TCP/IPv4) and click Properties to open the Internet Protocol Version 4 (TCP/IPv4) Properties window shown in Figure 2. Configure the IPv4 address and subnet mask information, and default gateway. The DNS server addresses are the IPv4 addresses of the Domain Name System (DNS) servers, which are used to translate IP addresses to domain name.

Configuration Command Modes

Global Configuration Mode Line Configuration Mode Interface Configuration Mode

can a IP address be assigned to both physical ports and virtual interfaces?

IP addresses can be assigned to both physical ports and virtual interfaces on devices. A virtual interface means that there is no physical hardware on the device associated with it.

why do we use IP addresses

IP addresses is the primary means of enabling devices to locate one another and establish end-to-end communication on the Internet.. Each end device on a network must be configured with an IP address.

Automatic IP Address Configuration for End Devices

In a network, DHCP enables automatic IPv4 address configuration for every end device that has DHCP enabled. Imagine the amount of time it would consume if every time you connected to the network, you had to manually enter the IPv4 address, the subnet mask, the default gateway, and the DNS server. Multiply that by every user and every device in an organization and you see the problem. Manual configuration also increases the chance of misconfiguration by duplicating another device's IPv4 address. It is possible to display the IP configuration settings on a Windows PC by using the ipconfig command at the command prompt. The output will show the IPv4 address, subnet mask, and gateway information received from the DHCP server.

Interface Addressing Verification

In the same way that you use commands and utilities like ipconfig to verify a PC host's network configuration, you also use commands to verify the interfaces and address settings of intermediary devices like switches and routers. show ip interface brief command. This command is useful for verifying the condition of the switch interfaces.

Syntax Checker - Limiting Access to a Switch

Limit access to a switch. Encrypt all passwords. Secure the privileged EXEC access. Secure the console access. Secure the VTY access. Encrypt all passwords. Sw-Floor-1(config)# service password-encryption Sw-Floor-1(config)# Secure the privileged EXEC access with the password. Cla55. Sw-Floor-1(config)# enable secret Cla55 Sw-Floor-1(config)# Secure the console line. Use the password Cisc0. Allow login. Sw-Floor-1(config)# line console 0 Sw-Floor-1(config-line)# password Cisc0 Sw-Floor-1(config-line)# login SW-Floor-1(config-line)# Secure the first 16 VTY lines. Use the password Cisc0. Allow login. Sw-Floor-1(config)# line vty 0 15 Sw-Floor-1(config-line)# password Cisc0 Sw-Floor-1(config-line)# login Sw-Floor-1(config-line)# You have successfully limited access to a switch.

Interface Configuration Mode

Mode that allows you to configure a Cisco router or switch port with specific information, such as an IP address and mask. Symbol - Switch(config-if)#.

Operating Systems

PC OS allows users to interact with the computer User-computer interaction in PC OSs are often done via mouse, keyboard and monitor Cisco IOS is also an Operating System Cisco IOS allows users to interact with Cisco devices.

How to Configuring passwords

SW1(config)# enable secret cisco SW1(config)# enable password cisco Clear text

configure line command

Switch(config)# line console 0 Switch(config-line)# exit Switch(config)# (config-line)# to (config-if)# Switch(config-line)# interface FastEthernet 0/1 Switch(config-if)#

how to create a banner

Switch1>enable Switch1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Switch1(config)#banner motd # Enter TEXT message. End with the character '#'. This device is for authorized personnel only. If you have not been provided with permission to access this device - disconnect at once. # Switch1(config)#banner login # Enter TEXT message. End with the character '#'. *** Login Required. Unauthorized use is prohibited *** # Switch1(config)#banner exec # Enter TEXT message. End with the character '#'. *** Ensure that you update the system configuration *** *** documentation after making system changes. *** # Switch1(config)#exit

you access the IOS using another intermediary device over a network connection.

Telenet/SSH

End-to-End Connectivity Test

The ping command can be used to test connectivity to another device on the network or a website on the Internet.

what is the structure of an IPv4 address called?

The structure of an IPv4 address is called dotted decimal notation and is represented by four decimal numbers between 0 and 255. IPv4 addresses are assigned to individual devices connected to a network.

Terminal Emulation Programs

There are a number of excellent terminal emulation programs available for connecting to a networking device either by a serial connection over a console port or by a SSH/Telnet connection. Some of these include: • PuTTY • Tera Term • SecureCRT • OS X Terminal

User EXEC Mode (user mode)

This mode has limited capabilities but is useful for basic operations. It allows only a limited number of basic monitoring commands but does not allow the execution of any commands that might change the configuration of the device. The user EXEC mode is identified by the CLI prompt that ends with the > symbol.

Privileged EXEC Mode

To execute configuration commands, a network administrator must access privileged EXEC mode. Higher configuration modes, like global configuration mode, can only be reached from privileged EXEC mode. The privileged EXEC mode can be identified by the prompt ending with the # symbol.

Cisco IOS modes of Operation

To initially configure a Cisco device, a console connection must be established. Once consoled in, the network technician will have to navigate through various command modes of the IOS CLI. The Cisco IOS modes use a hierarchical structure and are quite similar for both switches and routers.

Line Configuration Mode

Used to configure console, SSH, Telnet, or AUX access. Symbol - Switch(config-line)#

Purpose of OS

a GUI, a PC operating system enables a user to: Use a mouse to make selections and run programs Enter text and text-based commands View output on a monitor A CLI-based network operating system like the Cisco IOS on a switch or router enables a network technician to: Use a keyboard to run CLI-based network programs Use a keyboard to enter text and text-based commands View output on a monitor Cisco networking devices run particular versions of the Cisco IOS. The IOS version is dependent on the type of device being used and the required features. While all devices come with a default IOS and feature set, it is possible to upgrade the IOS version or feature set to obtain additional capabilities.

Why does each link on the Internet require a specific network media type?

each link on the Internet require a specific network media type, but each link also requires a particular network technology. For example, Ethernet is the most common local area network (LAN) technology used today. Ethernet ports are found on end-user devices, switch devices, and other networking devices that can physically connect to the network using a cable.

what does write erase do?

erase nvram

IOS Help Features

he IOS has two forms of help available: Context-Sensitive Help Command Syntax Check Context-sensitive help enables you to quickly find which commands are available in each command mode, which commands start with specific characters or group of characters, and which arguments and keywords are available to particular commands. To access context-sensitive help, simply enter a question mark, ?, at the CLI. Command syntax check verifies that a valid command was entered by the user. When a command is entered, the command line interpreter evaluates the command from left to right. 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.