CA Ex S1M06 Addressing the Network-IPv4

7/28/2019 CA Ex S1M06 Addressing the Network-IPv4

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Network Fundamentals Chapter 6

Addressing the Network IPv4

CCNA Exploration version 4.0


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Hc vin mng Bch Khoa - Website: www.bkacad.com 2

Objectives

Explain the structure IP addressing and demonstrate the abilityto convert between 8-bit binary and decimal numbers.

Given an IPv4 address, classify by type and describe how it isused in the network Explain how addresses are assigned to networks by ISPs and

within networks by administrators

Determine the network portion of the host address and explainthe role of the subnet mask in dividing networks.

Given IPv4 addressing information and design criteria, calculatethe appropriate addressing components.

Use common testing utilities to verify and test networkconnectivity and operational status of the IP protocol stack on ahost.


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Labs


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Introduction

Addressing is a key function of Network layer protocols thatenables data communication between hosts on the samenetwork or on different networks.

Designing,implementing andmanaging aneffective IPv4addressing planensures that ournetworks canoperate effectivelyand efficiently.


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IPv4 Addresses


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IP Addressing Structure

32-bit address

is expressed inDotted decimal

Network portion

Host portion

Octet

6.1.1


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Binary to Decimal Conversion

6.1.2.1

Positional

Notation


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Binary to Decimal Conversion

6.1.2.2


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6.1.3 Practice Activity



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Decimal to Binary Conversions

6.1.4.1

most-significant bit

(msb)


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6.1.4.2


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6.1.4.3


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6.1.5 Practicing Decimal to Binary Conversion



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Subnet Mask


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Defining the Network and Host Portions

The subnet mask is 32-bit pattern andcreated by placing a binary 1 in each bit position that

represents the network portion and placinga binary 0 in each bit position that

represents the host portion.

The prefix and the subnet mask are differentways of representing the same thing - thenetwork portion of an address.

6.4.1


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00000000 = 0

10000000 = 128 11000000 = 192 11100000 = 224 11110000 = 240 11111000 = 248

11111100 = 252 11111110 = 254

11111111 = 255


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ANDing

ANDing process: extracts the networkaddress from the IP address.

Logical AND:1 AND 1 = 1

1 AND 0 = 00 AND 1 = 0

0 AND 0 = 0

6.4.2


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The ANDing Process

6.4.3


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Addresses for Different Purposes


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Type of Address in an IPv4 Network

1. Network address - The address by which we refer tothe network. All hosts in a network will have the samenetwork bits.

2. Broadcast address - A special address used to senddata to all hosts in the network. The broadcastaddress uses the highest address in the network

range. This is the address in which the bits in the host

portion are all 1s. This address is also referred to asthe directed broadcast.

3. Host addresses - The addresses assigned to theend devices in the network

Three types of addresses 6.2.1


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6.2.1.2

The prefix length is the

number of bits in the address

that gives us the network

portion.


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Calculating addresses

6.2.2.1


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Network, Hosts & Broadcast Addresses

6.2.2.2


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Types of Communication

Unicast:

Is used for the normal host-to-host communication inboth a client/server and a

peer-to-peer network.

Uses the host address ofthe destination device asthe destination address and

can be routed through aninternetwork.

6.2.3.1


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Types of Communication

Broadcast:

The process of sending apacket from one host to allhosts in the network

Host processes abroadcast addressdestination packet likeunicast address.

A directed broadcast is sent to allhosts on a specific network.

The limited broadcast is used forcommunication that is limited to the

hosts on the local network.

6.2.3.2


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Lab 6.2.3.4



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Reserved IPv4 Address Ranges

6.2.4


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Q/A: Host Addresses

Which are addresses withinthe address range used for

special purpose ?


6.2.4

Q/A M l i Add


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Q/A: Multicast Addresses

Link Local addresses ? Global scopred addresses ?


6.2.4

P bli d P i t dd


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Public and Private addresses

6.2.5

P bli d P i t dd


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Public and Private addresses

Private Addresses: are set aside for use in privatenetworks.

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)

Public Addresses: are designed to be used in thehosts that are publicly accessible from the Internet.

Network Address Translation (NAT): is used totranslate private addresses to public addresses, be

implemented on a device at the edge of the privatenetwork.

A ti it 6 2 5 2


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Activity 6.2.5.2


Special IPv4 Addresses


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Network Addresses Broadcast Addresses Default Route

0.0.0.0/0 Link-Local Addresses

169.254.0.0 to 169.254.255.255 (169.254.0.0 /16) These addresses can be automatically assigned TEST-NET Addresses

The address block 192.0.2.0 to 192.0.2.255

(192.0.2.0 /24) is set aside for teaching and learningpurposes. These addresses can be used indocumentation and network examples. Unlike theexperimental addresses, network devices willaccept these addresses in their configurations

6.2.6



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Legacy IPv4 Addressing


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6.2.7

Classful Addressing



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Limits to the Class-based SystemClassful allocation of address

space often wasted manyaddresses, which exhausted the

availability of IPv4 addresses.



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Classless AddressingAddress blocks appropriate to the

number of hosts are assigned tocompanies or organizations withoutregard to the unicast class.


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Assigning Addresses

Planning to Address the Network


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1. Preventing duplication of addresses: each host in aninternetwork must have a unique address.

2. Providing and controlling access: Some hosts provideresources to the internal network as well as to the externalnetwork. If the addresses for these resources are not plannedand documented, the security and accessibility of the devicesare not easily controlled.

3. Monitoring security and performance: As part of themonitoring process, we examine network traffic looking foraddresses that are generating or receiving excessive packets.

The allocation of these addresses inside the networks

should be planned and documented for the purpose of:

6.3.1.1



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Within a network, there are different types of

hosts:End devices for users

Servers and peripherals

Hosts that are accessible from theInternet

Intermediary devices



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An important part of planning an IPv4 addressing schemeis deciding when private addresses are to be used andwhere they are to be applied. Considerations:

1. Number of devices connected to the networkmore than public addresses allocated by the

network's ISP?2. Need to be accessed from outside the local

network?

3. Supports NAT service?

6.3.1.2



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Assigning Addresses


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Assigning Addresses

Static Assignment: The network administrator mustmanually configure the network information for a host.

6.3.2.1

Benefits ?

Assigning Addresses


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g g

Dynamic Host Configuration Protocol (DHCP): enables theautomatic assignment of addressing information such as IP address,subnet mask, default gateway, and other configuration information.

6.3.2.2

Benefits ?

Assigning Addresses to Other Devices


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6.3.3

Who Assigs the Different Addresses ?


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g

Internet Assigned Numbers Authority (IANA) (http://www.iana.net ) is the master holder of the IP

addresses.

6.3.4

ISPs


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6.3.5

Internet Backbone ?

ISPs: Tier 1


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The primary advantages for customers of Tier 1 ISPs are reliability and speed. The drawback for Tier 1 ISP customers is its high cost.

ISPs: Tier 2


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Tier 2 ISPs generally focus on business customers. These tier 2 ISPs tend to have the IT resources to operate their own services such as DNS, e-

mail servers, and web servers.

The primary disadvantage of Tier 2 ISPs, as compared to Tier 1 ISPs, is slower Internetaccess.

ISPs: Tier 3


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

While they may have reduced bandwidth and lessreliability than Tier 1 and Tier 2 providers, they are oftengood choices for small to medium size companies.

Overview of IPv6


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6.3.6

Overview of IPv6


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Creating expanded addressing capabilitieswas the initial motivation for developing this

new protocol. Other issues were also considered during

the development of IPv6, such as:

Improved packet handling

Increased scalability and longevity

QoS mechanismsIntegrated security

Overview of IPv6


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1. 128-bit hierarchical addressing - to expandaddressing capabilities

2. Header format simplification - to improvepacket handling

3. Improved support for extensions and options- for increased scalability/longevity and improved

packet handling

4. Flow labeling capability - as QoS mechanisms5. Authentication and privacy capabilities - to

integrate security

To provide these features, IPv6 offers:

Overview of IPv6


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IPv6 is not merely a new Layer 3 protocol - it is anew protocol suite.

Because of the increased size of the IPv6 header,it also impacts the underlying network

infrastructure.


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Calculating Addresses

Basic subnetting


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6.5.1.1

Formula for calculating subnets


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The number of subnets = 2^n (n= thenumber of bits borrowed) The number of hosts per network = 2^n -2

(n= number of host bits)


Basic subnetting


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6.5.1.2

Basic subnetting


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6.5.1.3

FLSM vs VLSM


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Fixed Length Subnet Mask Variable Length Subnet Mask



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Dividing Networks into Right Sizes


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6.5.2.2

http://www.vlsm-calc.net/


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Subnetting a Subnet


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6.5.4 Determining the Network Address


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6.5.5 Calculating the Number of Hosts


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Lab 6.5.7


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Lab 6.5.8


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Testing the Network Layer

Testing the Local Stack


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Pinging the Local Loopback: 127.0.0.1

6.6.1

Testing Connectivity to the Local LAN


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Ping Gateway

6.6.2

Testing Connectivity to Remote LAN


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Use ping to verify that a local host can communicate via agateway to a device in remote network

6.6.3.1

Lab 6.6.3.2-Ping


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Testing the Path


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Use tracert/traceroute command

6.6.4.1

Round Trip Time ?

Lab 6.6.4.2- Trace Route


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ICMP v4 The Protocol supporting Testing and Messaging


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ICMP is the messaging protocol for the TCP/IP suite.ICMP provides control and error messages and is used

by the ping and traceroute utilities. ICMP messages that may be sent include: Host confirmation

Unreachable Destination or Service Time exceeded Route redirection Source quench

6.6.5

ICMPv4


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The purpose of these messages is toprovide feedback about issues related tothe processing of IP packets under certainconditions, not to make IP reliable.

ICMP messages are not required and areoften not allowed for security reasons.

Lab 6.7.1 6.7.5


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Q&A


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Refer to the exhibit. Which network prefix will implement

the IP addressing scheme for the LANs shown in thegraphic?


Q&A


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Refer to the exhibit. Host A is connected to the LAN, but itcannot get access to any resources on the Internet. Theconfiguration of the host is shown in the exhibit. Whatcould be the cause of the problem?


Q&A


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The devices are recommended to beassigned static IP addresses:

serversnetwork printers

routersSwitchs

firewalls


Q&A


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Which of the following are features ofIPv6

larger address space

data types and classes of service

authentication and encryption


Summary


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200H (/24)


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200H (/24)

107.1.0.0 lan1 107.1.1.0lan6

107.1.2.0 107.1.3.0


100H 90H


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100H, 90H 107.1.2.0/24 /15

.2.0 2.128


50H


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50H 107.1.3.0/24 -/26 .3.0 lan 4

.3.64 .3.128

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30H


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30H .3.64/26 /27 3.64 Lan5

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Link 2H


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Link 2H .3.96/27 /30 .3.96

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Documents

CA Ex S1M06 Addressing the Network-IPv4