CCNA Exploration Chapter 1Planning and Cabling a Network

V 4.0

1.1.1 What are the common components between a router and other computers?

CPU, RAM, ROM, Operating System

1.1.1.2 What does a router connect? Connects multiple networks

What does a router do with each packet it receives?

The router forwards the packet to either the destination of the packet, or another network that will lead it to its destination

What are the 2 types of connections to a router interface?

LANs and WANs

1.1.1.3 What are the two primary functions of a router?

Determine the best path to send packets and forwarding the packets toward their destination.

What address does the router use to compare to the routing table?

The destination IP address

What two processes are used by a router to learn about remote networks and build their routing tables?

Static routes and dynamic routing protocols

1.1.2 What are the five components common to all routers?

RAM, ROM, Power supply, Fan, and AIM

1.1.2.2 List the 5 different components stored in RAM.

Operating System, Running Configuration File, IP routing table, APR Cache, and Packet Buffer

What happens to the information in RAM if the router looses power?

The content is lost

What are the permanent storage areas in a router?

ROM, flash, and NVRAM

What 3 things are stored in ROM?

Bootstrap instructions, Basic diagnostic software and scaled down version of IOS

What is stored in flash? Permanent storage for Cisco IOSWhat happens to flash memory when the power is lost?

Nothing

What is stored in NVRAM? All configuring changes such as startup configuration file and running configuration file changes

What must you do to save changes you have made to a router?

Save the contents to the NVRAM before powering off

1.1.3 What is the most common method used for configuring a router?

CLI interface

What is the first thing that happens as the router boots up?

Startup-configuration file is copied into the RAM and stored as the running-configuration file.

1.1.4 What are the 4 phases of the bootup process?

1. Performing the POST2. Loading bootstrap program3. Locating and loading Cisco IOS software4. Locating and loading the startup

configuration file or entering setup modeWhat does POST test? Router hardwareWhat is the main function of the bootstrap program?

Locate the Cisco IOS and load it to RAM

What are the 2 main places to find the IOS?

Flash memory or on a TFTP server

If a full IOS can not be loaded what does the bootstrap loader do?

Load a scaled down version of IOS to diagnose issues to be able to load a complete version of IOS into RAM

Where is the startup configuration found?

In the NVRAM

What are the main items stored in the configuration file?

Interface addresses, routing information, passwords, any other configurations saved by the network administration

Where is the second place that the router looks for the startup config if it is not located in NVRAM?

TFTP server

If the router can not locate a startup-config, what mode does it enter?

Setup mode

What key command do you press to exit setup mode if you accidentally entered it?

Ctrl-C

1.1.4.2 What command can be used to help verify and troubleshoot some of the basic hardware and software components of the router?

Show version

What is the last line displayed in the show version output?

Current configured value of the software configuration register in hexadecimal

What is the default configuration register setting?

0x2102

What does that setting tell the He router will attempt to load a Cisco IOS

router? software image from the flash memory and load the startup configuration file from NV RAM

1.1.5 What are the two management ports?

Console port and Auxiliary port

What is an interface? Physical connector on the router whose main purpose is to receive and forward packets

1.1.5.2 What must be configured for each interface?

IP address and subnet mask of a different network

What are the two major groups of router interfaces?

LAN and Wan

1.1.6 What OSI layer does a router operate at?

Network Layer

1.1.6.2 What is the router interface that connects to a LAN called?

Ethernet

What is the process that each router uses to determine where to send the packet?

Decapsulation, searching routing table, then re-encapsulation

1.2.1 What are the four essential information elements to include in the topology diagram?

Device names, interfaces used in the design, IPaddresses and subnet masks, and Default gateway addresses for end devices such as PCs

1.2.2 What are the basic tasks to perform when configuring a router?

Name router, set passwords, configure interfaces, configure banner, save changes, verify basic configure and router operations

What is the prompt for the user mode?

Router>

What is the command to enter the privileged EXEC mode?

enable

What is the prompt for privileged EXEC mode?

Router#

What is the command to enter the global configuration mode?

Config t

What is the command to enter the hostname of a router?

Hostname *(insert name here)*

What happens to the prompt after you press enter?

(inserted name here)#(config)

What is the command used to enter the password to enter the privileged EXEC mode?

Enable secret class

List the commands to set the password for the console port?

Line con 0Password ciscolineLoginExit

List the commands to set the password for the Telnet lines?

Line vty 0. 4Password ciscovtyLoginexit

List the commands to enter the Banner Message of the Day (motd).

Banner motd #(insert text here) #

What should the banner show? Warn against unauthorized access1.2.2.2 What is the command to enter

the interface configuration mode?

Interface (line name)

What is the command to set the IP address and subnet mask for an interface?

IP addr (address) (subnet mask)

What is the command to enter a description for the interface?

Description (information)

What is the command to turn on an interface?

No shutdown

1.2.2.3 What is the command to view the running-configuration file?

Show running-config

What is the command to save the current config in NVRAM?

Copy running-config startup-config

What command will display the routing table?

Show IP route

What command displays all of the interface configuration parameters and statistics?

Show interfaces

What command displays abbreviated interface configuration information, including IP address and interface status?

Show ip interface brief

1.3.1 Where is the routing table stored?

Data file in RAM

What is a directly connected network?

Network directly attached to one of the router interfaces

What is a remote network? Network not directly connected to the routerWhat would a C in the first column of a routing table mean?

Directly connected route

What additional information is included when the destination is a remote network?

Routing metric and administrative distance

What command reveals the configured or acquired default gateway, connected, loopback, multicast, and broadcast networks?

Show ip route

1.3.2.1 How does a PC determine which network it belongs to?

Its host IP address and subnet mask

What command will activate a router interface?

No shutdown

What routes does a router know before any static or dynamic routing is configured?

Directly connected networks

1.3.3 What denotes a static route in the routing table?

Code S

What are the three items that must be included in a static route?

Ip address, subnet mask, next hop

When should static routes be used?

A network only has a few routers, connected to the internet through a single ISP or is configured in a hub-and-spoke topology

1.3.4 What are dynamic routing protocols used for?

Share information about reachability and status of remote networks

What are 2 of the activities that dynamic routing protocols perform?

Network discovery, and updating and maintaining routing tables

What is network discovery? Ability of a routing protocol to share info about networks it knows with other routers that are using the same routing protocol

What are some dynamic routing protocols?

RIP, IGRP, EIGRP, OSPF, IS_IS, and BGP

1.3.5 What are the three routing principles?

1. Every router makes its decision alone2. The fact that one router has certain info in

its routing table does not mean that other routers have the same info

3. Routing info about a path from one network to another does not provide routing info about the reverse or return path

What is asymmetric routing? Packets traverse the network in one direction and return via another path

1.4.2 What does a router compare to select the best path to place in the routing table?

Hop count and Bandwidth

What is a metric? Quantitative value used to measure the distance to a given route

What is the best path? Path with the lowest metric

The number of routers that a packet must travel through before reaching its destination is called?

Hop count

The data capacity of a link, sometimes referred to as the speed of the link?

Bandwidth

1.4.3 What is it called when two paths to a destination have exactly the same metric?

Equal cost load balancing

What is equal cost load balancing?

When a routing table has 2 or more paths with the same metric to the same destination network.

1.4.4 What are the two functions of packet forwarding?

Path determination and switching function

1.4.5 What is the process used by a router to accept a packet on one interface and forward it out another interface called?

Packet switching

What are the three major steps a router performs on a packet? 1. Decapsulates the Layer 3 packet by

removing the Layer 2 frame header and trailer.

2. Examines the destination IP address of the IP packet to find the best path in the routing table.

3. Encapsulates Layer 3 packet into a new Layer 2 frame and forwards the frame out the exit interface

What happens to the value of the TTL as a packet moves through a network?

It decrements the TTL by one

Which address does not change as the packet moves through the network?

Layer 3 IP address

Which address changes as the packet moves through the network?

Layer 2 data link address

1.4.5.2 How does a PC determine which network it belongs to?

By performing an AND operation on its own IP address and subnet mask which results in its network address.

How does it determine if the destination is on the same network?

The AND operation will result the same network

Where does the PC send the packet if the destination is not on its own network?

Forward the packet back to the router

Where does the PC look for the default gateway MAC address?

Checks its ARP table for the mac address of the default gateway

What does the PC do if the MAC address is not in the ARP table?

Sends an ARP request to the router

1.5.2-4 Excellent description of how a packet travels from one pc to another. Make certain you understand the steps. Note any questions you have about the process.

A packet travels from one pc to another is when a data is broken in to small pieces. Then another computer will receive the packet, and it will send an acknowledgement packet. By sending an acknowledgement to the other computer, it shows that it received the data. Then it also shows it is ready to receive more data.