TEJ3M
NETWORKING & IP ADDRESSING
NETWORKING & IP ADDRESSING
Networking is the communication between computer systems or devices. A computer network is any set of computers or devices connected to each other with the ability to exchange data. The three types of networks are:
the Internet: The network formed by the co-operative interconnection of millions of computers, linked together is called Internet
intranet: Internal private networks built within an organization using Internet and World Wide Web standards and products that allows employees of an organization to gain access to corporate information
extranet:It is the type of network that allows users from outside to access the Intranet of an organization
The main difference between extranets and intranets is that intranets are internal networks that are accessible only to employees, while extranets are extended networks that allow external parties to access certain parts of an organization's intranet. Intranets are used for internal communication, collaboration, and operations management, while extranets are used for external communication and collaboration with customers, suppliers, and partners. Having an extranet makes an organization vulnerable
Examples of different network methods are:
Personal area network (PAN): short range small networks. Typically wireless and allows transfer of data between devices (e.g. cellphone to tablet)
Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building. The group of computers and devices are connected together by a switch, or stack of switches, using a private addressing scheme as defined by the TCP/IP protocol
Wireless LANs and WANs (WLAN & WWAN) are the wireless equivalent of the LAN and WAN.
Metropolitan area network (MAN), which is used for medium size area. examples for a city or a state. ISP-level networks
Wide area network (WAN) that is usually a larger network that covers a large geographic area.
All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, power lines and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet). Networking, routers, routing protocols, and networking over the public Internet have their specifications defined in documents called RFCs.
All computers on a network have to know how to talk to each other. This requires a 'protocol' (which is a set of rules that dictate how computers can talk to each other). Think of a protocol being like a language. Both computers have to speak the same language. The model used in networking is known as the OSI model which will be discussed in a future topic in the course.
Essentially the way your computer (phone/console/computer/'smart refrigerator' etc...) talks to another computer is that packets of information are created by the computer. They move to the network interface, then across a medium (copper/glass/air) to a receiving network interface that then hands the information 'up' to the relevant application on the next computer.
To find the other computer there are network appliances. A network appliance is one that tells packets of information where to go. Think of appliances as a "Hello Girl" back in the age of manual telephone switching. They take incoming packets of information and read where they're supposed to go and then redirect them on their way towards their destination. The most common appliances we see as consumers are switches and routers.
A switch typically redirects packets in internal networks while a router redirects information across the internet. This is done through routing tables which will be discussed as we get further into networking
The big technological leap forward in networking was the advent of the UTP (unsheilded twisted pair) - most commonly used today as category 5 (or 6).
UTP category and its associated speed
What is a computer network? Provide an example.
What is a network protocol? Provide an example.
What are 4 different types of network media?
What is the difference between a network hub and a network switch?
What is an IP Address?
What is a MAC address?
For each of the following pieces of network hardware, briefly describe its function and provide a picture.
Network Router
Network Switch
Network Bridge
Repeater
Wireless Access Point
Network Cable (you pick the type)
Network Interface Controller (NIC)
Of the network components listed in question 7, which ones do you have in your house?
Implemented in 1998, Internet Protocol version 4 addressing was/is a connectionless protocol (a message can be sent from one location to another without a prior connection being formed) for use on packet-switched networks (e.g., Ethernet). It operates on a best effort delivery model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an upper layer transport protocol (e.g., Transmission Control Protocol). All that to say, 'Information A' goes from one address to another by being broken down into packets, which make their way to the end-address the best they can, then get reassembled into 'Information A' once more.
Interestingly enough, the backbone of the internet, IPv4 is currently being replaced by IPv6 as a default protocol (e.g. Windows 10 by defaults assigns IPv4 and IPv6 address). The top-level IPv4 'exhaustion' occurred in 2011. Reserve addresses were exhausted between 2011 and 2019 depending on the area of the world you were in. Individual ISPs still have pools of unassigned IP addresses, and reclaim them as they are no longer needed by subscribers. Switching equipment to enable IPv6 was no easy task since there was cost associated with it.
An understanding of the way that IPv4 addressing works will help us to understand IPv6 addressing, so let's start there. In IPv4 addressing (let's just refer to it as IP addressing), an IP address is a 32 bit, 4 octet address which is assigned (by who?) to every computer on an IP (ethernet protocol) network.
For example, the host address 192.168.1.1 (which is a very common router address for most home networks) resolves to:
IP address is a 32 bit, 4 octet address assigned to every computer on an IP (Internet Protocol) network.
reminder:
111111112 = 25510
so:
00001010.10111100.00011100.00010000
10.190.28.17
Network and host addresses are like a real-world analogy: street address (ie I live on River Road) vs. street number (I'm at 1633 River Road)
1) Class A: Used by countries or VERY large companies (e.g. Cisco, Microsoft, Dell etc...). These are unique 1st octet ranges (1-> 127). They take the form of:
network.host.host.host
octet1.octet2.octet3.octet4
street address.housenumber.housenumber.housenumber
255^3 bits so about 16.5million host addresses
the default subnet mask (which creates subnets, or private addresses within the host network) for these is 255.0.0.0
2) Class B: Used by somewhat large companies (Bell, Videotron). The first octet is in the range of 128-191 and has the pattern:
network.network.host.host
63*255 class B networks which about 16k addresses
subnet mask is 255.255.0.0 so about (255x255) 65k host addresses inside
3) Class C: Used by small companies and individuals. The first octet is in the range 192-223 and has the pattern:
network.network.network.host
254 hosts per network
subnet mask is 255.255.255.0
4) Class D/E: are experimental networks used to multicast
Tools we use in IP networking are:
ipconfig: which gives information about the host computer's network adapters as well as the details of the connection to the ethernet network.
ping: which is a way in which to test the reachability of a host or IP address on a network.
traceroute: is a diagnostic tool for displaying the route (path) and measuring transit delays of packets across an Internet Protocol (IP) network.
There are several network IP addresses that reserved, they are:
10.host.host.host
127.host.host.host
169.host.host.host
192.host.host.host (chances are your home network is something like 192.168.X.X where the subnet IP addresses are likely 192.168.1.X or 192.168.2.X)
IP addresses conform to the pattern:
octet1.octet2.octet3.octet4
https://youtu.be/ThdO9beHhpA
Network Address: The network bits stay the same. Host bits all resolve to 0
Broadcast Address: Network bits stay the same, host bits all are 1s
Subnet Mask: Network bits binary 1's, Host bits binary 0's
First available address: the first host bit will be 1
Case 1: 172.168.14.11 (Class B: Network Network Host Host)
172.168.0.0
172.168.255.255
255.255.0.0
172.168.0.1
Case 2: 203.200.0.42 (Class C: Network Network Network Host)
203.200.0.0
203.200.0.255
255.255.255.0
203.200.0.1
Copy the google doc in classroom and complete and submit
Copy the google doc in classroom and complete and submit
https://youtu.be/mJ_5qeqGOaI?si=ANI6Kb8TzPHGZtTx
Where grade 11 starts:
Subnetting is where you divide a network into smaller networks. To do that you borrow host bits and make them into network bits. Why?
bandwidth control
security
Example. South Carleton wants to subnet its network for teachers, students, guests, caf and the library. (5 separate networks).
IP address is 10.0.0.0 (which is in the class A range though is protected)
a) class A means Network.Host.Host.Host
b) How many do we want to make? What is the # of host bits to borrow to accommodate this?
Take the following octet. You'll see what I put a line after the first 3 ones.
Thank you Sean
Generically calculating subnets is done by 2S where S is the number of bits borrowed (always take from the left). If we borrow 2 bits, that 22 =4. Not enough subnets. By borrowing 3 bits 23 =8 networks which is more than we need to satisfy our SCHS requirements. And in some cases (edge cases) subnets have reserved ranges, in which case we use 2S-2 = 6 subnets more on that in grade 12)
Calculating hosts is done by 2H-2 where H is the number of host bits left in the range. In this case 10.X.X.X we're borrowing 3 bits from octet #2 for the network, that leaves 5 for the host (and the last 2 octets would be an additional 8+8). So the number of hosts would be 5 + 8 + 8 bits = 21 bits so 221-2 = 2,097,150 hosts per subnet (-2 because the broadcast and network addresses per subnet)
c) Default subnet mask for a class A is 255.0.0.0. Our new subnet mask for 3 borrowed bits would be:
11111111.11100000.00000000.00000000
or 255.224.0.0
A vanilla class A has 8 network bits and since we're borrowing 3 MORE bits from octet 2, that's 8 original network bits, and 3 more so /11
255.224.0.0 /11
What about this case?
150.3.7.9 /20
A vanilla class B would have /16, so this is borrowing 4 bits from the 3rd octet.
2N = 4 = 16 subnets
The number of hosts would be 4 host bits left in the 3rd octet, and all 8 bits in the 4th octet, so a total of 12 host bits
2H = 212 -2 = 4096-2 = 4094 hosts per subnet
c) Default subnet mask for a class B is 255.255.0.0. Our new subnet mask for 4 borrowed bits would be:
11111111.11111111.11110000.00000000
or 255.255.224.0.
To understand how a router works, we need an IP address, a Subnet Mask and we need to use Boolean Logic.
Eg. 192.168.1.23 255.255.255.0
Routers only care about the Network bits. The Subnet Mask masks out the Host bits using Boolean Logic operation AND.
AND - both elements have to be True (1) for the end result to be True (1).
1 AND 1 = 1 (True)
1 AND 0 = 0 (False)
0 AND 1 = 0 (False)
0 AND 0 = 0 (False)
Eg. 1 0 1 0 1 0 0 0
AND 1 1 1 1 0 0 0 0
1 0 1 0 0 0 0 0
Example with a default subnet mask:
192.168.001.23
AND 255.255.255.0
11000000.10101000.00000001.00010111 ← 192.168.1.23
AND 11111111.11111111.11111111.00000000 ← 255.255.255.0
11000000.10101000.00000001.00000000 → 192.168.1.0
Example with a subnetted subnet mask: 172.172.33.4 255.255.240.0
172.172.33.4 → 10101100.10101100.00100001.00000100
255.255.240.0 → 11111111.11111111.11110000.00000000
172.172.32.0 ← 10101100.10101100.00100000.00000000
^^^^^
Subnet Address
More examples:
State the network address of the following subnetted networks (use Boolean Logic):
200.200.23.42 255.255.255.224
13.14.15.67 255.248.0.0
150.132.128.7 255.255.240.0
d) that means the following addresses for the subnet and the broadcast
each subnet increments by 32
10.32.0.1 min for subnet 1
10.32.255.254 max for subnet 1
the broadcasts are 001|1111 (far right nibble is max 63)
Borrowing Bits - How to tell how many bits have been borrowed from the Subnet Mask
To make subnets, you borrow bits from host bits and make them network bits
Class A - Network.Host.Host.Host (borrowing bits from 2nd octet)
255.0.0.0 (default subnet mask)
Class B - Network.Network.Host.Host (borrowing bits from 3rd octet)
255.255.0.0 (default subnet mask)
Class C - Network.Network.Network.Host (borrowing bits from 4th octet)
255.255.255.0 (default subnet mask)
Example 1 - Subnet Mask - 255.240.0.0 - Class A subnet mask
Binary - 11111111.11110000.00000000.00000000
4 bits borrowed from the 2nd octet (240)
Example 2 - Subnet Mask - 255.255.255.224 - Class C subnet mask
Binary - 11111111.11111111.11111111.11100000
3 bits borrowed from the 4th octet (224)
Example 3 - What would the Subnet Mask be for a Class B IP Address with 4 borrowed bits?
Default Class B Subnet Mask - 255.255.0.0
We borrow 4 bits from the 3rd octet → 11110000 = 240
Therefore, the new Subnet Mask is 255.255.240.0
Example 4 - What would the Subnet Mask be for a Class C IP Address with 7 borrowed bits?
Default Class C Subnet Mask - 255.255.255.0
We borrow bits from the 4th octet → 111111102 = 25410
Therefore, the new Subnet Mask is 255.255.255.254
Example 5 - What would the Subnet Mask be for a Class A IP Address with 2 borrowed bits?
Default Class A Subnet Mask - 255.0.0.0
We borrow bits from the 2nd octet → 110000002 = 19210
Therefore, the new Subnet Mask is 255.192.0.0
THAT SAID: Things aren't as simple as you thought - you can borrow bits from octets to the right PAST the 'regular' subnet mask. E.g. you can have a "class C" mask on a "class A" address. Why? when you have to have more hosts per subnet than 255
E.g. 12.14.1.0
with a mask of
255.255.240.0 (class B mask)
or 12.14.1.0
255.255.255.240 (class C mask)
Typically borrowing bits from the right is ok, however, you CAN borrow bits from the left (e.g. use a class B subnet mask on a class C address) in what is called classless addressing. Feel free to look up CIDR and VLSM classless masks
IP Address - 192.168.1.0/24 (/24 means this is the network portion of the address)
Class? - C
How many bits to borrow to make 4 subnets?
2N = number of subnets present (if N=2 then that's 4 subnets)
2H - 2 >= number hosts per subnets where H is the number of leftover bits (if we're borrowing 2 bits for N, that leaves 6 bits for host)
22 = 4 subnets which is 2 bits borrowed
26 -2 = 62 hosts per subnet
Default subnet mask 255.255.255.0
But the new subnet mask (with 2 bits borrowed for N)?
255.255.255.11000000 → 255.255.255.192
Subnet 1 - 192.168.1.0 (incrementing by 64)
Subnet 2 - 192.168.1.64
Subnet 3 - 192.168.1.128
MAJIK ChARt
Copy the google doc in classroom and complete and submit
For each of the following, state: the number of bits borrowed, the address class, the new subnet mask, the first three subnet addresses and the first three broadcast addresses.
1. Address of 202.22.22.0 and 14 subnets.
2. Address of 5.0.0.0 and 29 subnets.
3. Address of 198.22.22.0 and 2 subnets.
4. Address of 140.90.0.0 and 32 subnets.
5. Address of 150.150.0.0 and 65 subnets.
6. Address of 192.150.10.0 and 5 subnets.
7. Address of 225.98.12.0 and 42 subnets.
8. Address of 10.0.0.0 and 1000 subnets. (this one is bonus - you don't have to do it if you can't figure it out)
Packet Tracer is in the classroom for download
Logical Topology: how the various computers are organized from a communications perspective (star topology being common). Router ports make the subnets (Eg: E0,E1)
Logical Topology
Physical topology: how and WHERE devices are connected on a network
Logical (bottom left) and Physical (top right) topologies
Example:
A school has teachers, students and a library with a Class B address. Subnet and draw the logical topology
Teachers = 20
Students = 240
Library = 30
IP: 164.164.0.0
Describes the physical and logical layout of a network
Physical Topology: the actual (scaled) network
Logical Topology: how the various computers are organized from a communications perspective (star topology being common)
Physical network diagram - more like a blueprint
Logical Network diagram - more like a mind-map
Objective: This assignment aims to assess your understanding of computer networking, subnetting, and network design using Packet Tracer. You will be tasked with creating a network, implementing subnetting, configuring devices, and ensuring proper communication within the network. See list of address classes and number of bits borrowed for each student.
Scenario: You are given the task of setting up a network for a medium-sized company. The company has four departments: Sales, Marketing, Finance and IT. Your goal is to design a network that efficiently allocates IP addresses using subnetting and ensures secure communication between the departments.
Requirements:
Network Topology: Create a network in Packet Tracer with the following devices:
One Router.
Four Switches(one for each department).
Four PCs for Sales.
Four PCs for Marketing.
Four PCs for IT.
Four PCs for Finance
Subnetting: Implement proper subnetting to efficiently allocate IP addresses to each department based on your assignment IP addressing class and number of bits borrowed.
Router Configuration: Assign IP addresses to router interfaces according to your subnet design.
PC Configuration: Configure each PC with an IP address based on its department's subnet.
1) Google Doc with the work/logic behind your subnetting choices.
2) A Packet Tracer file (.pkt) that includes your network configuration to Google Classroom.
3) To easily exceed expectations head back to the lab and configure the router in the back using a laptop and a working home router
Materials:
length of cat6 UTP (unshielded twisted pair): has 4 pairs of copper wires which have colour coding
RJ45 jack
Tools:
scissors
crimper
tester
Steps:
measure cable and add 15% length and cut it
cut away outer coating to expose the twisted pairs. Don't nick the copper cables as you cut away the protective sheath
Put the cable colors in order (what is a straightthrough vs. crossover):
StraightThrough (A-A or B-B)
WG/G/WO/Bl/WBl/O/WBr/Br
Crossover (A-B or B-A)
WO/O/WG/Bl/WBl/G/WBr/Br
Flatten out the wires and trip them so about 2cm of wire are exposed
Slide the RJ45 jack onto the wires (gold side up). The jack should JUST slide down to the cable sheath
Check with your teacher
Crimp and test the cable
Cryptography is the study and practice of techniques for secure communication in the presence of third parties called adversaries. It deals with developing and analyzing protocols that prevents malicious third parties from retrieving information being shared between two entities thereby following the various aspects of information security. Secure Communication refers to the scenario where the message or data shared between two parties can’t be accessed by an adversary. In Cryptography, an Adversary is a malicious entity, which aims to retrieve precious information or data thereby undermining the principles of information security. Data Confidentiality, Data Integrity, Authentication and Non-repudiation are core principles of modern-day cryptography.
sourceNetwork security on the other hand are activities designed to protect the integrity of your network and data. They include both hardware and software technologies. The aim is to stops threats from entering or spreading on your network.
Key Usage: Uses the same secret key for both encryption and decryption.
Speed: Generally faster than asymmetric encryption because it uses shorter keys and simpler algorithms.
Security: Requires secure key distribution, as both parties need the same key.
Examples: Advanced Encryption Standard (AES), Data Encryption Standard (DES).
Use Cases: Ideal for encrypting large amounts of data, as the speed and simplicity are advantageous.
Key Usage: Uses a pair of keys: a public key for encryption and a private key for decryption.
Speed: Slower than symmetric encryption due to more complex algorithms and longer keys.
Security: Enhanced security as the private key never needs to be shared, and the public key can be distributed widely.
Examples: RSA, Diffie-Hellman.
Use Cases: Ideal for secure key exchange and digital signatures
Hash Functions
A hash function takes an input (data of any size) and produces a fixed-size output (the hash or message digest).
Hash functions are designed to be one-way, meaning it's computationally infeasible to reverse the process and find the original input from the hash.
A good hash function should produce unique hashes for different inputs, and even a small change in the input should result in a drastically different hash.
How CAs (Certificate Authorities) Use Hash Functions:
Digital Signatures: When a CA signs a certificate, it calculates the hash of the certificate's data (e.g., subject information, public key).
Private Key Encryption: The CA then encrypts this hash using its private key, creating a digital signature.
Verification: Anyone can verify the signature by decrypting it with the CA's public key and recalculating the hash of the original data. If the decrypted hash matches the recalculated hash, the signature is valid, and the data is considered authentic and unaltered.
The reason to use Hash Functions
Data Integrity: Hash functions ensure that the data being signed hasn't been tampered with during transmission or storage.
Efficiency: Using a hash function allows the CA to sign a small, fixed-size hash instead of the entire data, which is more efficient.
Security: Hash functions are crucial for secure digital signatures, password storage, and other cryptographic applications.
Examples:
SSL/TLS: Hash functions are used in the SSL/TLS handshake to authenticate parties and establish secure connections.
Password Storage: Instead of storing passwords in plain text, systems often store the hash of the password (often with a salt) to enhance security.
File Integrity Checks: Hash functions can be used to verify that a downloaded file hasn't been corrupted during the download process.
The last section of cryptography we'll discuss is the art of hiding data within other files (like images, audio, or text) to conceal its existence. It is called steganography and while it relies on hiding data, and not necessarily encrypting it, it can be combined with encryption for added security, making the hidden message even harder to detect.
At its most basic, steganography embeds clusters of data inside of a 'regular picture', but otherwise the picture appears normal. More advanced steganography uses image keys to extract the data from another image.
Head to this website
Create a message in the Text Encryption box
Use Encrypt with a custom secret key. Make sure your partner has that same key though a direct google chat message.
Record your encrypted message output to this form for your partner to decipher
Look up the encrypted message from your partner and use the key you both agreed upon to decipher it
Guest speaker
CIA triad, is a fundamental model in information security that emphasizes the importance of Confidentiality, Integrity, and Availability of data and systems