Router Boot-up Process

Router Boot-up Process

There are four major phases to the bootup process:
1. Performing the POST
2. Loading the bootstrap program
3. Locating and loading the Cisco IOS software
4. Locating and loading the startup configuration file or entering setup mode

1. Performing the POST
The Power-On Self Test (POST) is a common process that occurs on almost every computer during bootup. The POST process is used to test the router hardware. When the router is powered on, software on the ROM chip conducts the POST. During this self-test, the router executes diagnostics from ROM on several hardware components including the CPU, RAM, and NVRAM. After the POST has been completed, the router executes the bootstrap program.

2. Loading the Bootstrap Program
After the POST, the bootstrap program is copied from ROM into RAM. Once in RAM, the CPU executes the instructions in the bootstrap program. The main task of the bootstrap program is to locate the Cisco IOS and load it into RAM.
Note: At this point, if you have a console connection to the router, you will begin to see output on the screen.

3. Locating and Loading Cisco IOS
Locating the Cisco IOS software. The IOS is typically stored in flash memory, but can also be stored in other places such as a TFTP (Trivial File Transfer Protocol) server.
If a full IOS image can not be located, a scaled-down version of the IOS is copied from ROM into RAM. This version of IOS is used to help diagnose any problems and can be used to load a complete version of the IOS into RAM.
Note: A TFTP server is usually used as a backup server for IOS but it can also be used as a central point for storing and loading the IOS. IOS management and using the TFTP server is discussed in a later course.

4. Locating and Loading the Configuration File
Locating the Startup Configuration File. After the IOS is loaded, the bootstrap program searches for the startup configuration file, known as startup-config, in NVRAM. This file has the previously saved configuration commands and parameters including:
interface addresses
routing information
passwords
any other configurations saved by the network administrator
If the startup configuration file, startup-config, is located in NVRAM, it is copied into RAM as the running configuration file, running-config.
Executing the Configuration File. If a startup configuration file is found in NVRAM, the IOS loads it into RAM as the running-config and executes the commands in the file, one line at a time. The running-config file contains interface addresses, starts routing processes, configures router passwords and defines other characteristics of the router.

Enter Setup Mode (Optional). If the startup configuration file can not be located, the router prompts the user to enter setup mode. Setup mode is a series of questions prompting the user for basic configuration information. Setup mode is not intended to be used to enter complex router configurations, and it is not commonly used by network administrators.
When booting a router that does not contain a startup configuration file, you will see the following question after the IOS has been loaded:

Command Line Interface
Depending on the platform and IOS, the router may ask the following question before displaying the prompt:
Would you like to terminate autoinstall? [yes]:
Press the Enter key to accept the default answer.
Router>
Note: If a startup configuration file was found, the running-config may contain a hostname and the prompt will display the hostname of the router.
Once the prompt displays, the router is now running the IOS with the current running configuration file. The network administrator can now begin using IOS commands on this router.
Note: The bootup process is discussed in more detail in a later course.

CCNA Exam Topic : Planning & Designing

CCNA Exam Topic : Planning & Designing

CCNA Planning & Designing topic explains all the actual and real questions that would be on ccna test.

Question 1:
Which of the following host addresses are members of networks that can be routed across the public Internet?(Choose three.)
A. 10.172.13.65
B. 172.16.223.125
C. 172.64.12.29
D. 192.168.23.252
E. 198.234.12.95
F. 212.193.48.254

Answer: CEF

Explanation:
Private IP address scheme
Class A: 10.0.0.0 – 10.255.255.255
Class B: 172.16.0.0 – 172.31.255.255
Class C: 192.168.0.0 – 192.168.255.255
Other then private ip addresses remaining IP’s addresses are routed across internet.

Question 2:
Given a subnet mask of 255.255.255.224, which of the following addresses can be assigned to network hosts?
(Choose three.)
A. 15.234.118.63
B. 92.11.178.93
C. 134.178.18.56
D. 192.168.16.87
E. 201.45.116.159
F. 217.63.12.192

Answer: BCD

Explanation:
For calculating network hosts range for subnet 255.255.255.224
Simple method to find out network subnet is 256 -224 = 32
Write down the multiples of 32 to get subnet networks
Host range for subnet 255.255.255.224 are between this ranges below
0 ----- 31 (0 is network address and 31 is broadcast address)
32 -----63
64 -----95
96 -----127
128 ----159
160---- 191
192 ----223
224 ----255

Question 3:
When variable length subnet masking is used, what does the term route aggregation describe?
A. calculating the total number of available host addresses in the AS
B. combining routes to multiple networks into one supernet
C. reducing the number of unusable addresses by creating many subnets from one supernet
D. reclaiming unused address space by changing the subnet size

Answer: B

Explanation:
Route aggregration is an effort to route smaller prefixes via an aggregated larger prefix (supernetting). The advantage is obvious: Many /24 networks, for example, could be aggregated to larger networks like /23, /22 or even bigger prefixes.

Question 4:
ABC Company is merging with several local businesses that use routers from multiple vendors. Which routing protocol would work best to connect ABC Company with the enterprise networks it has acquired by providing scalability and VLSM support while minimizing network overhead?

A. RIP v1
B. RIP v2
C. IGRP
D. OSPF
E. EIGRP

Answer: D

Explanation:
Since only OSPF,EIGRP and RIPv2 supports VLSM in above options. It requires working with multi vendor and providing scalability OSPF is best choice of the three mentioned.

Question 5:
Which of the following IP addresses fall into the CIDR block of 115.64.4.0/22? (Choose three.)
A. 115.64.8.32
B. 115.64.7.64
C. 115.64.6.255
D. 115.64.3.255
E. 115.64.5.128
F. 115.64.12.128

Answer: BCE

Explanation:
/22 is 8bits + 8bits + 6bits i.e 11111111.11111111.11111100.0
Third octet 11111100 = 128+64+32+16+8+4
= 252 therefore subnet mask is 255.255.252.0
Subnet networks are 256-252= 4
Host range for above subnet are
0------- 3
4 ------ 7

Host that fall under 115.64.4.0 /22 networks are
4 5 6 7

Question 6:
In the implementation of VLSM techniques on a network using a single Class C IP address, which subnet mask is the most efficient for point-to-point serial links?
A. 255.255.255.0
B. 255.255.255.240
C. 255.255.255.248
D. 255.255.255.252
E. 255.255.255.254

Answer: D

Explanation:
For point-to-point serial link exist only two hosts so the best possible subnet mask for two useable hosts for class C network is 255.255.255.252

Question 7:
Which statements are true regarding classless routing protocols? (Choose two.)
A. The use of discontiguous subnets is not allowed.
B. The use of variable length subnet masks is permitted.
C. RIP v1 is a classless routing protocol.
D. IGRP supports classless routing within the same autonomous system.
E. RIP v2 supports classless routing.

Answer: BE

Question 8:

The company internetwork is subnetted using 29 bits. Which wildcard mask should be used to configure an extended access list to permit or deny access to an entire subnetwork?
A. 255.255.255.224
B. 255.255.255.248
C. 0.0.0.224
D. 0.0.0.8
E. 0.0.0.7
F. 0.0.0.3

Answer: E

Explanation:
29 bits subnet is 8bits + 8bits + 8bits + 5bits
255.255.255.(5bits)
11111000 = 128+64+32+16+8+0+0+0
= 248
Subnet is 255.255.255.248
Simple method to calculate the Wildcard mask from known subnet is to
Reverse 1’s into 0’s and 0’s into 1’s from the binary representation of subnet.
For above example (248 = 11111000 subnet)
11111000 (subnet) = 00000111 (wildcard mask) last octet.
= 7 (wildcard mask) for last octet.
Converting the remaining first 3 octets of subnet into wildcard mask using above method
Resulted wildcard mask is 0.0.0.7

Question 9:
The MDA Company is implementing dialup services to enable remote office employees to connect to the local network. The company uses several different Layer 3 protocols on the network. Authentication of the users connecting to the network is required for security. Additionally, some employees will be dialing long distance and will need callback support. Which protocol is the best choice for these remote access services?
A. 802.1
B. Frame relay
C. HDLC
D. PPP
E. SLIP
F. PAP

Answer: D

Question 10:
Refer to the diagram. All hosts have connectivity with one another. Which statements describe the addressing scheme that is in use in the network? (Choose three.)

A. The subnet mask in use is 255.255.255.192.
B. The subnet mask in use is 255.255.255.128.
C. The IP address 172.16.1.25 can be assigned to hosts in VLAN1
D. The IP address 172.16.1.205 can be assigned to hosts in VLAN1
E. The LAN interface of the router is configured with one IP address.
F. The LAN interface of the router is configured with multiple IP addresses.

Answer: BCF

Question 11:
Which routing protocols will support the following IP addressing scheme? (Choose three.)
A. RIP version 1
B. RIP version 2
C. IGRP
D. EIGRP
E. OSPF

Answer: BDE

Question 12:
A company with 25 computers decides to connect its network to the Internet. The company would like for all of the computers to have access to the Internet at the same time, but the company only has four usable public IP addresses. What should be configured on the router so that all computers can connect to the Internet simultaneously?
A. static NAT
B. global NAT
C. dynamic NAT
D. static NAT with ACL’s
E. dynamic NAT with overload

Answer: E

Question 13:
A network administrator would like to implement NAT in the network shown in the graphic to allow inside hosts to use a private addressing scheme. Where should NAT be configured?

A. Corporate router
B. Engineering router
C. Sales router
D. all routers
E. all routers and switches

Answer: A

Question 14:
Which of the following describe private IP addresses? (Choose two.)
A. addresses chosen by a company to communicate with the Internet
B. addresses that cannot be routed through the public Internet
C. addresses that can be routed through the public Internet
D. a scheme to conserve public addresses
E. addresses licensed to enterprises or ISPs by an Internet registry organization

Answer: BD

Question 15:
Refer to the graphic. A host is connected to switch port Fa0/3 with a crossover cable. The host and switch have been fully configured for IP connectivity as shown. However, the port indicator on switch port Fa0/3 is not on, and the host can not communicate with any other hosts including those connected to VLAN 2 on the same switch. Based on the information given, what is the problem?
A. Switch port Fa0/3 is not configured as a trunk port.
B. The cable is the wrong type.
C. The switch has been assigned an incorrect subnet mask.
D. Switch port Fa0/3 has been blocked by STP.
E. The switch and the hosts must be in the same subnet.

Answer: B

Explanation:
Straight through cable is used to connect a host to switch.

Question 16:
What kind of cable should be used to establish a trunked link between two Catalyst 2950 switches?
A. a straight-through cable
B. an EIA/TIA-232 serial cable
C. an auxiliary cable
D. a modem cable
E. a cross-over cable

Answer: E

Explanation:
Cross-over cable is used to connect two switches.

Question 17:
What is the purpose of Spanning Tree Protocol?
A. to prevent routing loops
B. to create a default route
C. to provide multiple gateways for hosts
D. to maintain a loop-free Layer 2 network topology
E. to enhance the functions of SNMP

Answer: D

Question 18:
The network 172.25.0.0 has been divided into eight equal subnets. Which of the following IP addresses can be assigned to hosts in the third subnet if the ip subnet-zero command is configured on the router? (Choose three.)
A. 172.25.78.243
B. 172.25.98.16
C. 172.25.72.0
D. 172.25.94.255
E. 172.25.96.17
F. 172.25.100.16

Answer: ACD

Question 19:
Which wild card mask will enable a network administrator to permit access to the Internet for only hosts that are assigned an address in the range of 192.168.8.0 through 192.168.15.255?
A. 0.0.0.0
B. 0.0.0.255
C. 0.0.255.255
D. 0.0.7.255
E. 0.0.3.255

Answer: D

Question 20:
The exhibit shows a company network. The network administrator would like to permit only hosts on the 172.30.16.0/24 network to access the Internet. Which wild card mask and address combination will only match addresses on this network? A. 172.30.0.0 0.0.0.0
B. 172.30.16.0 0.0.0.255
C. 172.30.0.0 0.0.15.255
D. 172.30.16.0 0.0.31.255
E. 172.30.16.0 0.0.255.255

Hotspot 2: Topology Question

Hotspot 2: Topology Question

640-802 CCNA Hotspot Topology Exhibit

Question 1:
Note: host 172.30.4.4 is wrongly given in Question the correct host must be 172.30.0.4



Answers: 702

Explanation:
The destination layer 2 address is a DLCI for frame-relay network. The destination host packet address is 172.30.0.4 corresponding DLCI is 702.
This can be confirmed by looking at the show frame-relay map output which shows the frame-relay map statements for layer 3 address to its corresponding layer 2 address IP 172.30.0.4 is mapped to DLCI 702 .

Question 2:

Answers: frame-relay map ip 172.30.0.3 196 broadcast

Explanation:

The show frame-relay map command above output provides the dynamic mapping for S-AMER (.3 as per topology the complete address is 172.30.0.3) to DLCI 196.

To create a static frame-relay map on dubai router to S-AMER we use the following command

Syntax: frame-relay map protocol protocol-address dlci [broadcast]

frame-relay map ip 172.30.0.3 196 broadcast

Question 3:

Answers: The serial connection to the MidEast branch office

Explanation:

By seeing the partial running config provided for Dubai router ... We can identify what encapuslation type is configured on each interface

Interface serial 1/0 : encapsulation frame-relay

Interface serial 1/2 and serial 1/3 : Both have encapsulation ppp

Interaface serial 1/1: Has no config info on encapsulation type this determines the default encapsulation (HDLC) is not changed on this interface.

Serial 1/1 is connection to MidEast branch office from Dubai router which has the default encapsulation.

Question 4:

Answers: T1net