Section 7: Introducing the TCP/IP Internet Layer, IPv4 Addressing, and Subnets

You want to subnet your 10.0.0.0/8 network to create 31 subnets. You determine that you need to apply the subnet mask 255.248.0.0. What is the range of available host addresses for the first subnet?

10.0.0.1 to 10.7.255.254

You have been assigned the network address 192.168.7.0/24. You assume that you need to establish 13 subnets, so you apply the subnet mask 255.255.255.240. What will be your second subnet address?

192.168.7.16

Which option is the binary representation of 80?

01010000

Which option correctly defines the digits that are used in the binary number system?

1 and 0

What is the Class A private IP range?

10.0.0.0/8 (10.0.0.0 - 10.255.255.255)

What is the binary equivalent of the decimal number 183?

10110111

What is the binary equivalent of the decimal number 192?

11000000

Which option is the decimal representation of 10000000?

128

You have subnetted your 192.168.36.0 network address with a 255.255.255.240 mask. How many subnets and hosts per subnet are available?

16 subnets and 14 hosts per subnet

How many valid host addresses are available for each subnet after subnetting network 172.16.0.0/16 by borrowing two host bits?

16382

What is the Class B private IP range?

172.16.0.0/12 (172.16.0.0 - 172.31.255.255)

What is the Class C private IP range?

192.168.0.0/16 (192.168.0.0 - 192.168.255.255)

What is the IPv4 directed broadcast IP for the subnet address of 192.168.11.32/28?

192.168.11.47

Which of these addresses is the assigned subnet address for the host address 192.168.3.50/27?

192.168.3.32

You have a host 192.168.50.2/24. What is its network address?

192.168.50.0

Which two IPv4 address blocks are assigned for use in documentation and example code?

203.0.113.0/24 198.51.100.0/24

What is the decimal equivalent of the binary number 11100000?

224

How many host addresses can be used in a network with a /24 mask that has not been subnetted?

254

A large company has a /8 network but needs to subnet it into 1000 subnets. Which subnet mask segments the /8 network and provides the maximum number of hosts per subnet?

255.255.192.0

You have been assigned the network 172.16.0.0/16. You need to establish 13 subnets. What is the new subnet mask in the decimal form?

255.255.240.0

A company currently has a network range of 192.168.54.0/24. The company wants to subnet this range into 4 subnets, each supporting at least 50 users. Which subnet mask would you recommend?

255.255.255.192

You are designing an IPv4 addressing scheme for a branch office. The branch office is assigned to the 172.16.32.0/25 subnetwork, so you have one subnet (172.16.32.0) with 126 host addresses available to you. However, you can see from your design branch office topology that the largest LAN will only require 11 host addresses. If you want to avoid wasting address space and allocate addresses efficiently, you will need to subnet your subnetwork further, which means applying the VLSM. Which subnet mask should you use to achieve the desired scheme?

255.255.255.240

You are designing an IPv4 addressing scheme for a branch office. The branch office is assigned to the 192.168.1.64/26 subnetwork, so you have one subnet (192.168.1.64) with 62 host addresses that are available to you. You need at least 4 subnets with 14 hosts each. Which subnet mask should you use to achieve the desired scheme?

255.255.255.240

You have been assigned a /24 network address. A coworker has requested that you create 10 subnets that can support 10 hosts per network. Which subnet mask should you use?

255.255.255.240

How many subnets and host addresses per subnet are created by borrowing 8 bits from a 172.16.0.0/16 network?

256 subnets with 254 host addresses per subnet

How many bits are contained in an IPv4 address?

32 bits

How many valid host addresses are available for each subnet after subnetting network 192.168.0.0/24 by borrowing two host bits?

62

What is the decimal representation of 01000000?

64

By borrowing three host bits, how many subnets are created?

8

You have subnetted your 192.168.36.0 network address with a 255.255.255.224 mask. How many subnets are available?

8

What type of reserved IPv4 address is used before the host has a valid IPv4 address assigned via DHCP?

All zeros address (0.0.0.0)

The first bit of this classful address is always a 0

Class A

This classful address block has a value between 1 and 126 in the first octet

Class A

This classful address block is designed to support extremely large networks with more than 16 million host addresses

Class A

The first 2 bits of this classful address is always a binary 10

Class B

This classful address block has a value between 128 and 191 in the first octet

Class B

This classful address block is designed to support the needs of moderate to large networks with more than 65,000 hosts

Class B

The first 3 bits of this classful address is always a binary 110

Class C

This classful address block has a value between 192 to 223 in the first octet

Class C

This classful address block is designed to support the needs of small networks with a max of 254 hosts

Class C

This classful address space is the most commonly available address class

Class C

The first 4 bits of this classful address is always a binary 1110

Class D

This classful address block has a value between 224 to 239 in the first octet

Class D

This classful address block is dedicated to multicast applications

Class D

This classful address block only carries the destination address and never the source address

Class D

Which two IPv4 address classes are considered as special cases, and are never assigned to hosts as source IPv4 addresses?

Class D Class E

The first 4 bits of this classful address is always a binary 1111

Class E

This classful address block has a value between 240 to 255 in the first octet

Class E

This classful address block is reserved by the IANA as a block of experimental addresses

Class E

This classful address block should never be assigned to IPv4 hosts

Class E

How are the number of hosts created for a subnet calculated?

Find the last borrowed 1-bit value of the subnet mask octet and subtract 2 or add the number of host bits and use the following calculation: 2^h - 2

This field in the IPv4 header sets various control flags regarding fragmentation

Flag

This field in the IPv4 header indicates where a specific fragment belongs

Fragment offset

This field in the IPv4 header is used for header error detection

Header checksum

Within a subnet mask, what is the part of the address that corresponds to having binary 0's?

Host ID

What type of reserved IPv4 address is in 169.254.0.0/16 range?

IPv4 autoconfiguration address

You will mostly see this address as a failure condition when a PC fails to obtain an address via DHCP

IPv4 autoconfiguration address

What type of reserved IPv4 address is 172.16.255.255 in context of the network address 172.16.0.0/16?

IPv4 directed broadcast

What type of reserved IPv4 address is assigned to the address blocks of 198.51.100.0/24 and 203.0.113.0/24?

IPv4 documentation address

What type of reserved IPv4 address is 255.255.255.255?

IPv4 local broadcast

This field in the IPv4 header is used for unique fragment identification

Identification

This field in the IPv4 header describes the length of the header

Internet Header Length (IHL)

This is a packet that is a self-contained and independent entity that contains data and sufficient information to be routed from the source to the destination without reliance on previous packets.

Internet Protocol (IP)

This uses packets to carry Information through the network.

Internet Protocol (IP)

Which option correctly describes the network ID portion of the IPv4 address?

It identifies the network of which the host is a part.

Which option correctly describes the service type field in the IPv4 header?

It provides information on the desired quality of service.

What is a possible problem within a broadcast domain?

Larger amounts of broadcast traffic consume resources.

Which two aspects can present a problem with a flat network design?

Larger amounts of broadcast traffic consume resources. All devices share the same broadcast domain.

What layer of the the OSI reference layer does IP operate in?

Layer 3 or the network layer

Which type of reserved IPv4 address is 127.0.0.1?

Loopback

Class A addresses 127.0.0.0 to 127.255.255.255 cannot be used. What is this range reserved for?

Loopback and diagnostic functions

Within a subnet mask, what is the part of the address that corresponds to having binary 1's?

Network ID

Which two approaches should you use to verify the IPv4 address on an Apple Mac computer?

Open the Terminal and use the ifconfig command. Choose System Preferences > Network and choose the desired connection.

This field in the IPv4 header includes optional parameters

Options

This field in the IPv4 header is used to ensure that the header ends on a 32-bit boundary

Padding

This field in the IPv4 header indicates the upper-layer protocol that is used in the data portion of an IPv4 packet

Protocol

This field in the IPv4 header provides information on the desired quality of service

Service type

Which two statements about a network that uses subnetworks are true?

Smaller networks are easier to manage. Overall traffic is reduced.

This is a 32-bit number that describes which portion of an IPv4 address refers to the network ID and which part refers to the host ID

Subnet mask

What does the TTL value (in the TTL field) in the IPv4 packet header represent?

The TTL value limits the lifetime of a packet.

What does the Total Length value in the IPv4 packet header represent?

The Total Length value describes the length of a packet, including header and data.

How are the number of subnets calculated?

The total number of 1 bit's used to create the subnet = s, then use the following calculation: number of subnets = 2^s

This field in the IPv4 header describes the version of IP

Version

Which number system is the foundation of all computer operations?

binary

What kind of topology is an OSI Layer 2 - switch-connected network where all devices see all the broadcasts in the Layer 2 broadcast domain?

flat topology/network

Which CLI command should you use to verify the IPv4 address on an Apple or Linux computer?

ifconfig

At which layer of the TCP/IP stack does IP operate?

internet layer

What is the command within Cisco IOS Software that will enable/disable directed broadcast?

ip directed broadcast no ip directed broadcast

Which CLI command should you use to verify the IPv4 address on a Windows computer?

ipconfig

At which layer of the OSI reference model does IP operate?

network layer

Determine which class the IPv4 address 10.71.121.31 belongs to and whether it belongs to the range of the public or private IPv4 addresses. Which option represents the correct description?

private, Class A

What advantage do subnetworks provide?

scalability

This segments the hosts within the network

subnet