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Chapter 1 1
IP-V4 Addressing
Network Fundamentals – Chapter 6
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Objectives
1. convert between 8-bit binary and decimal numbers.
2. classful/classless addressing & Subnet mask
3. calculate the appropriate addressing components.
Network / Broadcast Addresses
4. Types of addresses in an IPv4 network
5. ANDING Process.
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IP Addressing Structure Describe the dotted decimal structure of a binary IP
address and label its parts
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The anatomy of an IPv4 address
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IPv4 Addresses An IP address has two parts:
network number
host number
Which bits refer to the network number?
Which bits refer to the host number?
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Dividing the Network and Host Portions
Subnet Mask
Used to define the:
Network portion
Host portion
32 bits
Contiguous set of 1’s followed by a contiguous set of 0’s
1’s: Network portion
0’s: Host portion
11111111111111110000000000000000
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Dividing the Network and Host Portions
Expressed as:
Dotted decimal
Ex: 255.255.0.0
Slash notation or prefix length
/16 (the number of one bits)
11111111.11111111.00000000.00000000
Dotted decimal: 255 . 255 . 0 . 0
Slash notation: /16
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IPv4 Addresses
Newer technology - Classless IP Addressing
The subnet mask determines the network portion and the host portion.
Value of first octet does NOT matter (older classful IP addressing)
Hosts and Classless Inter-Domain Routing (CIDR).
Classless IP Addressing is what is used within the Internet and in most internal networks.
Older technology - Classful IP Addressing (later)
Value of first octet determines the network portion and the host portion.
Used with classful routing protocols like RIPv1.
The Cisco IP Routing Table is structured in a classful manner (CIS 82)
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Classful IP Addressing
When an organization received an IP network address, that address was associated with a “Class”, A, B, or C.
This is known as Classful IP Addressing
The first octet of the address determined what class the network belonged to and which bits were the network bits and which bits were the host bits.
There were no subnet masks.
It was not until 1992 when the IETF introduced CIDR (Classless Interdomain Routing), making the address class meaning less.
This is known as Classless IP Addressing.
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Class A addresses
Network Host Host Host
First octet is between 0 – 127, begins with 0
Number
between 0 - 127
8 bits 8 bits 8 bits
With 24 bits available for hosts,
there a 224 possible addresses.
That’s 16,777,216 nodes!
There are 126 class A addresses.
0 and 127 have special meaning and are not used.
16,777,214 host addresses, one for network address and one for broadcast address.
Only large organizations such as the military, government agencies, universities, and large corporations have class A addresses.
For example ISPs have 24.0.0.0 and 63.0.0.0
Class A addresses account for 2,147,483,648 of the possible IPv4 addresses.
That’s 50 % of the total unicast address space, if classful was still used in the Internet!
Default Mask: 255.0.0.0 (/8)
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Class B addresses
Network Network Host Host
First octet is between 128 – 191, begins with 10
Number
between
128 - 191
8 bits 8 bits
With 16 bits available for hosts,
there a 216 possible addresses.
That’s 65,536 nodes!
There are 16,384 (214) class B networks.
65,534 host addresses, one for network address and one for broadcast address.
Class B addresses represent 25% of the total IPv4 unicast address space.
Class B addresses are assigned to large organizations including corporations (such as Cisco, government agencies, and school districts).
Default Mask: 255.255.0.0 (/16)
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Class C addresses
Network Network Network Host
First octet is between 192 – 223, begins with 110
Number
between
192 - 223
8 bits
With 8 bits available for hosts,
there a 28 possible addresses.
That’s 256 nodes!
There are 2,097,152 possible class C networks.
254 host addresses, one for network address and one for broadcast address.
Class C addresses represent 12.5% of the total IPv4 unicast address space.
Default Mask: 255.255.255.0 (/24)
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IPv4 Address Classes
Class D Addresses
A Class D address begins with binary 1110 in the first octet.
First octet range 224 to 239.
Class D address can be used to represent a group of hosts called a host group, or multicast group.
Class E Addresses First octet of an IP address begins with 1111
Class E addresses are reserved for experimental purposes and should not be used for addressing hosts or multicast groups.
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Fill in the information…
1. 192.168.1.3 Class ________ Default Mask:_____________________
Network: _____________________ Broadcast: _____________________
Hosts: _____________________ through _____________________
2. 1.12.100.31 Class ________ Default Mask:_____________________
Network: _____________________ Broadcast: _____________________
Hosts: _____________________ through _____________________
3. 172.30.77.5 Class ________ Default Mask:_____________________
Network: _____________________ Broadcast: _____________________
Hosts: _____________________ through _____________________
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Fill in the information…
1. 192.168.1.3 Class C Default Mask: 255.255.255.0
Network: 192.168.1.0 Broadcast: 192.168.1.255
Hosts: 192.168.1.1 through 192.168.1.254
2. 1.12.100.31 Class A Default Mask: 255.0.0.0
Network: 1.0.0.0 Broadcast: 1.255.255.255
Hosts: 1.0.0.1 through 1.255.255.254
3. 172.30.77.5 Class B Default Mask: 255.255.0.0
Network: 172.30.0.0 Broadcast: 172.30.255.255
Hosts: 172.30.0.1. through 172.30.255.254
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Class C Default Mask: 255.255.255.0 Network: 192.168.1.0
Class A Default Mask: 255.0.0.0 Network: 1.0.0.0
Class B Default Mask: 255.255.0.0 Network: 172.30.0.0
Class separates network from host bits
The Class determines the Base Network Mask!
1. 192.168.1.3
2. 1.12.100.31
3. 172.30.77.5
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Know the classes! (Write this out)
First First Network Host
Class Bits Octet Bits Bits
A 0 0 – 127 8 24
B 10 128 - 191 16 16
C 110 192 - 223 24 8
D 1110 224 – 239
E 1111 240 -
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IP addressing crisis
Address Depletion
Internet Routing Table Explosion
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Classless IP Addressing
The subnet mask determines the network portion and the host portion.
Value of first octet does NOT matter (older classful IP addressing)
Classless IP Addressing is what is used within the Internet and in most internal networks.
IP Add.======= 172.16.2.5
Subnet mask=== 255.255.255.0
Subnet== 172.16.2.0
Is not the default mask
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Example 1
Network Address: 192.168.1.0
Subnet Mask: 255.255.255.0
192.168.1.0
Network Host
Network Address in binary:
11000000.10101000.00000001.00000000
Subnet Mask in binary:
11111111.11111111.11111111.00000000
Prefix Length: /24
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Example 2
Network Address: 172.0.0.0
Subnet Mask: 255.0.0.0
172.0.0.0
Network Host
Network Address in binary:
10101100.00000000.00000000.00000000
Subnet Mask in binary:
11111111.00000000.00000000.00000000
Prefix Length : /8
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Example 3
Network Address: 172.0.0.0
Subnet Mask: 255.255.0.0
172.0.0.0
Network Host
Network Address in binary:
10101100.00000000.00000000.00000000 Subnet
Mask in binary:
11111111.11111111.00000000.00000000
Prefix Length: /16
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Subnet Masks – Your Turn!
Underline the network portion of each address:
Network Address Subnet Mask
172.0.0.0 255.0.0.0
172.16.0.0 255.255.0.0
192.168.1.0 255.255.255.0
192.168.0.0 255.255.0.0
192.168.0.0 255.255.255.0
10.1.1.0 /24
10.2.0.0 /16
10.0.0.0 /16
What is the other portion of the address?
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Subnet Masks – Your Turn! Underline the network portion of each address:
Network Address Subnet Mask
172.0.0.0 255.0.0.0
172.16.0.0 255.255.0.0
192.168.1.0 255.255.255.0
192.168.0.0 255.255.0.0
192.168.0.0 255.255.255.0
10.1.1.0 /24
10.2.0.0 /16
10.0.0.0 /16
What is the other portion of the address?
Host portion for host addresses
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Chapter 1 25
Network / Broadcast Addresses
Network Fundamentals – Chapter 6
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Types of addresses in an IPv4 network Name the three types of addresses in the network and
describe the purpose of each type
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Network / Broadcast Addresses - Network address :
the first IP address in it which all host part bits = 0
- Broadcast address:
the last IP address in the network which all host part bits = 1
no. of host bits
- other addresses are host addresses = 2 - 2
-Here are some examples:
Class Network Address Broadcast Address
A 12.0.0.0 12.255.255.255
B 172.16.0.0 172.16.255.255
C 192.168.1.0 192.168.1.255
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Types of Addresses
Network address - The address by which we refer to the network
Broadcast address - A special address used to send data to all hosts in the network
Host addresses - The addresses assigned to the end devices in the network
Network
Addresses have
all 0’s in the host
portion.
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Types of Addresses
Network address - The address by which we refer to the network
Broadcast address - A special address used to send data to all hosts in the network
Host addresses - The addresses assigned to the end devices in the network
Broadcast
Addresses have
all 1’s in the host
portion.
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Types of Addresses
Network address - The address by which we refer to the network
Broadcast address - A special address used to send data to all hosts in the network
Host addresses - The addresses assigned to the end devices in the network
Host Addresses
can not have all
0’s or all 1’s in the
host portion.
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Bringing it all together
Broadcast IP Address
Convert these addresses and masks to Binary (to be used later)
Network: 10.1.1.0 00001010.00000001.00000001.00000000
Mask: /24 11111111.11111111.11111111.00000000
Bcast: 10.1.1.255 00001010.00000001.00000001.11111111
Network: 10.2.0.0 00001010.00000010.00000000.00000000
Mask: /16 11111111.11111111.00000000.00000000
Bst:10.2.255.255 00001010.00000010.11111111.11111111
Network 10.0.0.0 00001010.00000000.00000000.00000000
Mask: /16 11111111.11111111.00000000.00000000
Bcast10.0.255.255 00001010.00000000.11111111.11111111
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Range of hosts – Your Turn! Network Address Subnet Mask Broadcast Address
172.0.0.0 255.0.0.0 172.255.255.255
172.0.0.1 through 172.255.255.254
172.16.0.0 255.255.0.0 172.16.255.255
172.16.0.1 through 172.16.255.254
192.168.1.0 255.255.255.0 192.168.1.255
192.168.1.1 through 192.168.1.254
192.168.0.0 255.255.0.0 192.168.255.255
192.168.0.1 through 192.168.255.254
192.168.0.0 255.255.255.0 192.168.0.255
192.168.0.1 through 192.168.0.254
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Range of hosts – Your Turn!
Network Address Subnet Mask Broadcast Address
10.1.1.0 /24 10.1.1.255
10.1.1.1 through 10.1.1.254
10.2.0.0 /16 10.2.255.255
10.2.0.1 through 10.2.255.254
10.0.0.0 /16 10.0.255.255
10.0.0.1 through 10.0.255.254
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Subnet Masks: Non-Natural Boundaries Subnet masks do not have to end on natural octet boundaries
172.1.16.0 10101100.00000001.00010000.00000000
255.255.240.0 11111111.11111111.11110000.00000000
172.1.16.1 10101100.00000001.00010000.00000001
172.1.16.2 10101100.00000001.00010000.00000010
172.1.16.3 10101100.00000001.00010000.00000011
…
172.1.16.255 10101100.00000001.00010000.11111111
172.1.17.0 10101100.00000001.00010001.00000000
172.1.17.1 10101100.00000001.00010001.00000001
…
172.1.31.254 10101100.00000001.00011111.11111110
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Subnet Masks: Non-Natural Boundaries Subnet masks do not have to end on natural octet boundaries
172.1.16.0 10101100.00000001.00010000.00000000
255.255.240.0 11111111.11111111.11110000.00000000
172.1.16.1 10101100.00000001.00010000.00000001
…
172.1.31.254 10101100.00000001.00011111.11111110
172.1.31.255 10101100.00000001.00011111.11111111
(broadcast)
Number of hosts: 212 – 2 = 4,096 – 2 = 4,094 hosts
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Subnet Masks: Non-Natural Boundaries
Subnet masks do not have to end on natural octet boundaries
192.168.1.0 11000000.10101000.00000001.00000000
255.255.255.224 11111111.11111111.11111111.11100000
192.168.1.1 11000000.10101000.00000001.00000001
192.168.1.2 11000000.10101000.00000001.00000010
192.168.1.3 11000000.10101000.00000001.00000011
…
192.168.1.29 11000000.10101000.00000001.00011101
192.168.1.30 11000000.10101000.00000001.00011110
192.168.1.31 11000000.10101000.00000001.00011111
(broadcast)
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Subnet Masks: Non-Natural Boundaries
Subnet masks do not have to end on natural octet boundaries
192.168.1.0 11000000.10101000.00000001.00000000
255.255.255.224 11111111.11111111.11111111.11100000
192.168.1.1 11000000.10101000.00000001.00000001
…
192.168.1.30 11000000.10101000.00000001.00011110
192.168.1.31 11000000.10101000.00000001.00011111
(broadcast)
Number of hosts: 25 – 2 = 32 – 2 = 30 hosts
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Given------------ IP Add. &subnet mask
Determine -----the network ID which this IP belongs.
------the broadcast IP Add. Of the network.
----the range of usable IP Addresses.
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Calculating network, hosts, and broadcast addresses
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Determine if this IP is network address or host address or broadcast address 172.16.5.0/23
Solution :
- subnet mask = 255.255.254.0
- interesting octet is 254
- hop count = 256 – 254 = 2
- The first subnet is 172.16.0.0/23
- The second subnet is 172.16.2.0/23
- The third subnet is 172.16.4.0/23
- The fourth subnet is 172.16.6.0/23
So 172.16.5.0/23 is a host address
172.16.5.0/23
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- Which IP address should be assigned to PC B ?
A . 192.168.5.5
B . 192.168.5.32
C . 192.168.5.40
D . 192.168.5.63
E . 192.168.5.75
192.168.5.33/27
?
A
B
Answer : C
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- Given the choices below, which address represents a unicast address?
Answer : E
A . 224.1.5.2
B . FFFF. FFFF. FFFF.
C . 192.168.24.59/30
D . 255.255.255.255
E . 172.31.128.255/18
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Chapter 1 43
Types of addresses in an IPv4 network
Network Fundamentals – Chapter 6
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Unicast, multicast, broadcast - types of communication
difference between limited B.C & directed B.C?
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Reserved IPv4 address ranges
Identify the address ranges reserved for these special purposes in the IPv4 protocol
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multicast address range
multicast address range is subdivided into different types of addresses:
reserved link local addresses(224.0.0.0 to 224.0.0.255 )
globally scoped addresses. (224.0.1.0 to 238.255.255.255)
administratively scoped addresses (239.0.0.0/8)
(limited scope addresses.)
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Private Addresses
The private address blocks are:
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)
With services to translate private addresses to public addresses, hosts on a privately addressed network can have access to resources across the Internet.
Public Addresses These addresses are designed to be used in the
hosts that are publicly accessible from the Internet.
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Public and private address
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Special IPv4 addresses Describe the purpose of several special addresses
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Special IPv4 addresses
Network and Broadcast Addresses
Default Route
Loopback
Link-Local Addresses
These addresses can be automatically assigned to the local host by the operating system in environments where no IP configuration is available
TEST-NET Addresses
Unlike the experimental addresses, network devices will accept these addresses in their configurations.
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Planning to address the network Explain the importance of using a structured process to
assign IP addresses to hosts and the implications for choosing private vs. public addresses
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Static or dynamic addressing for end user devices
Explain how end user devices can obtain addresses either statically through an administrator or dynamically through DHCP
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Who assigns the different addresses
Internet Assigned Numbers Authority (IANA)
Registration companies are called Regional Internet Registries (RIRs)
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ISP’s Identify different types of ISPs and their roles in
providing Internet connectivity
•The primary advantages for customers of Tier 1 ISPs are reliability and speed.
• Tier 2 ISPs generally focus on business customers.
• Tier 3 ISPs is the retail and home markets in a specific locale.
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ISP’s
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Overview of IPv6 Identify several changes made to the IP protocol in
IPv6 and describe the motivation for migrating from IPv4 to IPv6.
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Simpler header -E IP v.6 packet is simpler than IP v.4. (no fragmentation field).
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Ipv6 features
Large address space
No need for NAT/PAT
IPsec.
Transition tools
Header improvements
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Chapter 1 59
ANDING Process.
Network Fundamentals – Chapter 6
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Determine the network portion of the host address and the role of the subnet mask The prefix and the subnet mask are different ways of
representing the same thing - the network portion of an address.
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ANDing- What is in our network?
Use the subnet mask and ANDing process to extract the network address from the IP address.
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Determine the network portion of the host address and the role of the subnet mask Routers use ANDing to determine an acceptable route
for an incoming packet.
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Determine the network portion of the host address and the role of the subnet mask An originating host must determine if a packet should
be sent directly to a host in the local network or be directed to the gateway.
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Summary
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