SEMESTER 1 Chapter 6
Addressing the Network IPv4

 V 4.0

 

 

6.1.1

How many bits are the source and destination IPv4 addresses?

32 bits

 

What is the name for the decimal representation of the binary IP address called?

Dotted Decimal

 

How many bits are there between each “dot”?

8 bits

 

What are those bits called?

Octet

 

Define the network portion of an IP address?

a group of hosts that have identical bit patterns in the network address portion of their addresses

 

What is the host portion of the IP address?

Although all 32 bits define the IPv4 host address, we have a variable number of bits that are called the host portion of the address

 

What does the number of bits assigned to host determine?

the number of hosts that we can have within the network

6.1.2

What is the binary range in decimal of a byte?

0-255

The rest of 6.1

Binary conversions will be covered in the lab meeting?

 

6.2.1

Define a network address.

Within the IPv4 address range of a network, the lowest address is reserved for the network address.

 

Define a broadcast address.

The broadcast address uses the highest address in the network range.

 

Define a host address.

The addresses assigned to the end devices in the network.

 

What is the range where host addresses assigned?

Located between the network and the broadcast address.

6.2.1.2

What is assigned to determine how many bits are in network bits?

Prefix

 

Do the number of hosts that can be assigned stay the same when prefix changes?

No

6.2.2.1

How do you calculate the network value?

All host bits are 0

 

How do you calculate the first host value?

1 greater than the network address

 

How do you calculate the broadcast address?

All host bits are turned on

 

How do you calculate the last host address?

1 less than the broadcast address

6.2.2.2

This flash exercise is excellent practice for calculating the different values; you can do this until you have mastered the process. Please try it with prefix values of 24 and over so you have an example to go by.

 

6.2.3

Define unicast

the process of sending a packet from one host to an individual host

 

Define broadcast

the process of sending a packet from one host to all hosts in the network

 

Define multicast

the process of sending a packet from one host to a selected group of hosts

 

What is another name for a unicast address?

Host address

6.2.3.2

How does a host process a broadcast transmission?

it processes the packet as it would a packet to its unicast address

 

What is a broadcast transmission used for?

the location of special services/devices for which the address is not known or when a host needs to provide information to all the hosts on the network.

 

What are the three examples of broadcast transmissions?

Mapping upper layer addresses to lower layer addresses

Requesting an address

Exchanging routing information by routing protocols

 

When does a host send a broadcast?

When a host needs information, the host sends a request, called a query, to the broadcast address

 

How do hosts with the information usually respond to the broadcast?

One or more of the hosts with the requested information will respond, typically using unicast.

 

What is a directed broadcast?

A directed broadcast is sent to all hosts on a specific network.

 

What is a limited broadcast used for?

communication that is limited to the hosts on the local network

 

What forms the boundary for a broadcast domain?

Router

6.2.3.3

What is multicast designed to do?

conserve the bandwidth of the IPv4 network

 

What are the 4 examples of multicast transmissions?

Video and audio broadcasts

Routing information exchange by routing protocols

Distribution of software

News feeds

 

How are multicast addresses assigned?

The multicast clients use services initiated by a client program to subscribe to the multicast group.

 

What is the range for multicast addresses?

224.0.0.0 to 239.255.255.255

 

What is the range for experimental addresses?

240.0.0.0 to 255.255.255.254

6.2.5.1

List the three private address blocks? (This is incredibly important for network administrators to know)

10.0.0.0 to 10.255.255.255 (10.0.0.0 /8)

172.16.0.0 to 172.31.255.255 (172.16.0.0 /12)

192.168.0.0 to 192.168.255.255 (192.168.0.0 /16)

 

What happens if a packet with a private IP address was sent to the Internet?

It would not be forwarded

 

What is NAT Network Address Translation services used for?

to translate private addresses to public addresses, hosts on a privately addressed network can have access to resources across the Internet

 

How does NAT allow a host with a private address to access the Internet?

It allows the host to “borrow” a public IP address

6.2.5.2

Excellent practice. This is very important for the test.

 

6.2.6

What is the range for local-link addresses?

169.254.0.0 to 169.254.255.255

 

When is a local link address assigned to a device?

automatically assigned to the local host by the operating system in environments where no IP configuration is available

6.2.7

What is the first octet range of Class A?

1-126

 

What is the first octet range of Class B?

128-191

 

What is the first octet range of Class C?

192-223

 

What is the first octet range of Class D?

224-239

 

What is the first octet range of Class E?

240-255

 

What is the limitation of classful routing?

wasted many addresses, which exhausted the availability of IPv4 addresses

 

What is the address system used today called?

Classless addressing

 

Why should the allocation of addresses inside the networks be planned and documented for the purpose of?

Preventing duplication of addresses

Providing and controlling access

Monitoring security and performance

 

What are the different examples of types of hosts?

End devices for users

Servers and peripherals

Hosts that are accessible from the Internet

Intermediary devices

6.3.1.2

What considerations should be used about where private IP addresses should be used?

Will there be more devices connected to the network than public addresses allocated by the network's ISP?

Will the devices need to be accessed from outside the local network?

If devices that may be assigned private addresses require access to the Internet, is the network capable of providing a Network Address Translation (NAT) service?

6.3.2

Which devices should have static IP addresses assigned?

printers, servers, and other networking devices that need to be accessible to clients on the network

6.3.2.2

What does DHCP provide for an end device?

automatic assignment of addressing information such as IP address, subnet mask, default gateway, and other configuration information

 

What is the block of addresses a DHCP server use called?

Address pool

6.3.3

Which devices should have a static IP address? Why?

Servers and printers

So hosts can have consistent access

 

What does almost all traffic pass through when going between networks?

Intermediary Devices

 

Which IP addresses are used for router interfaces?

Lowest or Highest addresses in the range

6.3.4

What is the organization that assigns IP addresses in the US?

Internet Assigned Numbers Authority (IANA)

6.3.5

What are the advantages of having a Tier 1 ISP?

reliability and speed

 

What is the focus of a Tier 2 ISP?

focus on business customers

 

What is the focus of a Tier 3 ISP?

The focus of these ISPs is the retail and home markets in a specific locale.

6.3.6

What was the main issue to be addressed by IPv6?

Creating expanded addressing capabilities

 

What were the other issues that were considered when developing IPv6?

Improved packet handling

Increased scalability and longevity

QoS mechanisms

Integrated security

 

List the added features of IPv6.

128-bit hierarchical addressing - to expand addressing capabilities

Header format simplification - to improve packet handling

Improved support for extensions and options - for increased scalability/longevity and improved packet handling

Flow labeling capability - as QoS mechanisms

Authentication and privacy capabilities - to integrate security

6.4.1

How is the subnet mask created?

by placing a binary 1 in each bit position that represents the network portion and placing a binary 0 in each bit position that represents the host portion

 

What is true if the octet of the subnet mask is 255?

All of the octet is network/subnetwork bits.

 

What is true if the octet of the subnet mask is 0?

All of the octet is host bits.

6.4.2

What is the result of the ANDing process?

The network address

 

What is the only case in which ANDing results in a 1?

1 anded with a 1

6.5

We will cover this in class. Good exercises and examples to read through.

 

6.5.4-6

Excellent practice exercises, practice these a lot.

 

6.6.1

What is ping?

utility for testing IP connectivity between hosts

 

What happens when the destination host receives an echo request?

it responds with an ICMP Echo Reply datagram.

 

What is the address to ping the local host?

127.0.0.1

 

What does a response from the local host tell you?

that IP is properly installed on the host

 

What doesn’t the response from the local host tell you?

an indication that the addresses, masks, or gateways are properly configured

6.6.2

What does it tell you if a ping to the gateway is successful?

indicates that the host and the router's interface serving as that gateway are both operational on the local network

6.6.3

What does it tell you if a ping to the remote host is successful?

It means that we have verified our host's communication on the local network, the operation of the router serving as our gateway, and all other routers that might be in the path between our network and the network of the remote host.

6.6.4

What does the traceroute utility do?

allows us to observe the path between these hosts

 

Define Round Trip Time (RTT).

the time a packet takes to reach the remote host and for the response from the host to return

 

Define Time to Live (TTL).

When a packet enters a router, the TTL field is decremented by 1. When the TTL reaches zero, a router will not forward the packet and the packet is dropped.

6.6.5

What does ICMP provide for the TCP/IP protocol stack?

ICMP provides control and error messages and is used by the ping and traceroute utilities.

 

List the 5 ICMP messages that may be sent?

Host conformation

Unreachable Destination or Service

Time exceeded

Route redirection

Source quench

 

What are the 4 destination unreachable codes listed?

0 = net unreachable

1 = host unreachable

2 = protocol unreachable

3 = port unreachable