CN Unit 2 - Network Architecture and IP Addresses PDF

Unit 2 - Network architecture and IP address Ethernet Ethernet is the traditional technology for connecting devices in a wired local area network (LAN) or wide area network. It enables devices to communicate with each other via a protocol, which is a set of rules or common network language....

Unit 2 - Network architecture and IP address Ethernet Ethernet is the traditional technology for connecting devices in a wired local area network (LAN) or wide area network. It enables devices to communicate with each other via a protocol, which is a set of rules or common network language. Ethernet describes how network devices format and transmit data so other devices on the same LAN or campus network can recognize, receive and process the information Ethernet is used to connect devices in a network and is still a popular form of network connection. Specific organizations with local networks, such as company offices, school campuses and hospitals, use Ethernet for its high speed, security and reliability. Ethernet is the most widely used LAN technology and is defined under IEEE standards 802.3. The reason behind its wide usability is that Ethernet is easy to understand, implement, and maintain, and allows low-cost network implementation. Also, Ethernet offers flexibility in terms of the topologies that are allowed. Ethernet generally uses a bus topology. Ethernet operates in two layers of the OSI model, the physical layer and the data link layer. For Ethernet, the protocol data unit is a frame since we mainly deal with DLLs. Although Ethernet has been largely replaced by wireless networks, wired networking still uses Ethernet more frequently. Wi-Fi eliminates the need for cables by enabling users to connect their smartphones or laptops to a network wirelessly. Here are different types of Ethernet networks that are used to connect devices and transfer data. Let’s discuss them in simple terms: 1. Fast Ethernet: This type of Ethernet network uses cables called twisted pair or CAT5. It can transfer data at a speed of around 100 Mbps (megabits per second). Fast Ethernet uses both fiber optic and twisted pair cables to enable communication. There are three categories of Fast Ethernet: 100BASE-TX, 100BASE-FX, and 100BASE-T4. 2. Gigabit Ethernet: This is an upgrade from Fast Ethernet and is more common nowadays. It can transfer data at a speed of 1000 Mbps or 1 Gbps (gigabit per second). Gigabit Ethernet also uses fiber optic and twisted pair cables for communication. It often uses advanced cables like CAT5e, which can transfer data at a speed of 10 Gbps. 3.10-Gigabit Ethernet: This is an advanced and high-speed network that can transmit data at a speed of 10 gigabits per second. It uses special cables like CAT6a or CAT7 twisted-pair cables and fiber optic cables. With the help of fiber optic cables, this network can cover longer distances, up to around 10,000 meters. 4. Switch Ethernet: This type of network involves using switches or hubs to improve network performance. Each workstation in this network has its own dedicated connection, which improves the speed and efficiency of data transfer. Switch Ethernet supports a wide range of speeds, from 10 Mbps to 10 Gbps, depending on the version of Ethernet being used. In summary, Fast Ethernet is the basic version with a speed of 100 Mbps, Gigabit Ethernet is faster with a speed of 1 Gbps, 10-Gigabit Ethernet is Client and server architecture Network architecture means network layout tells us how computer are arranged and how task are allocated to the computer. Computer network architecture is defined as the physical and logical design of the software, hardware, protocols, and media of the transmission of data. There are two types of architecture of network architecture – 1. Peer-to-peer architecture 2. Client server architecture 1. Peer – to-peer architecture Peer-to-peer network is a network in which all the computer are linked together with equal privilege and responsibities for processing the data. Peer-to-peer network is useful for small environment, usually up to 10 computer. Peer-to-peer network has no dedicated server.  Special permission are assigned to each computer for sharing the resources but this can lead to a problem if the computer with the resource is down. Advantage – It is less costly as it does not contain any dedicated server. If one computer stops working but other computer will not stop working. It is easy to set up and maintain as each computer manages itself. Disadvantages – In the case of pee- to-peer network, it does not contain the centralized system. Therefore, it cannot backup the data as the data is different in different location. It has a security issue as the device is managed itself. 2.client server architecture – Client-server network is a network model designed for end users called clients to access the resources such as song, video, etc. from central computer known as server. The central controller is known as a server while all other computer is the network are called client. A server performs all the major operations such as security and network management. A server is responsible for managing all the resources such as files, directories, printers, etc. All the client communicate with each other through a server. For ex, if client 1 want to send some data to client2. Then it first send the request to the server for the permission. The server sends the  response to the client 1 to initiates its communication with the client2. Advantages – A client-server network contains the centralized system. Therefore we can back up the data easily. A client – server network has dedicated server that improves the overall performance of the whole system. Security is better in client-server network as a single server administers the shared resources. It also increases the speed of the sharing resources. Disadvantages – Client- server network is expensive as it requires the server with large memory. A server has a network operating system(NOS) to provide the resources to the client, but the cost of network operating system is very high. It requires a dedicated network administrator to manage all the resources. Internet verses intranet What is the Internet? The Internet is a global network that uses TCP / IP protocols to connect millions of computers worldwide. It can include different networks, such as private, public, organizational, academic, government, etc. It allows users to communicate with each other and share massive amounts of data in various formats. Internet is available in both modes, wired and wireless. In wired mode, the data travels through fiber optic cables, whereas in wireless mode, the data travels through radio waves. What is intranet An Intranet is a part of the Internet and is owned and used privately by an organization. It is mainly used to connect all the computers and establish a private network of an organization to provide employees the ability to collaborate on projects, manage or update information, share calendars, and to-do list, etc. Organizations prefer using Intranet to keep their data inaccessible from outsiders, making their suspicious data and project information secure. Intranet includes a firewall to prevent unauthorized users from accessing the network. Internet Intranet Internet is used to connect different Intranet is owned by private firms. networks of computers simultaneously. On the internet, there are multiple On an intranet, there are limited users. users. Internet is unsafe. Intranet is safe. On the internet, there is more number In the intranet, there is less number of visitors. of visitors. Internet is a public network. Intranet is a private network. In this, anyone can’t access the Anyone can access the Internet. Intranet. The Internet provides unlimited Intranet provides limited information. information. A company used to communicate Using Social media on your phone or internally with its employees and researching resources via Google. share information  Internet Intranet The Internet is a global network that An intranet is a private network that connects millions of devices and connects devices and computers computers worldwide. within an organization. It is open to everyone and allows An intranet is only accessible to access to public information, such as authorized users within the websites and online services. organization. An intranet is primarily used for It is used for communication, sharing of internal communication, information, e-commerce, education, collaboration, and information entertainment, and other purposes. sharing within an organization. Access to an intranet is restricted to Users can access the Internet from any authorized users within the location with an Internet connection and organization and is typically limited a compatible device. to specific devices and locations. Security measures, such as firewalls, Intranets employ similar security encryption, and secure sockets layer measures to protect against (SSL) protocols, are used to protect unauthorized access and ensure against threats like hacking, viruses, the privacy and integrity of shared and malware. data. The Internet is a public network that is Intranets are private networks that not owned by any particular are owned and managed by the organization or group. organization that uses them. Examples of intranet-based Examples of Internet-based services services include internal include email, social media, search communications, knowledge engines, and online shopping sites. management systems, and collaboration tools  Connection oriented and connectionless services to establish a connection between two or more devices, there are services in Computer Networks. There are two services that are given by the layers to layers above them. These services are as follows: 1. Connection-Oriented Service 2. Connectionless Services Connection-Oriented Services There is a sequence of operations to be followed by the users of connection-oriented service. These are: 1. The connection is established. 2. Information is sent. 3. The connection is released. In connection-oriented service, we have to establish a connection before starting the communication. When the connection is established, we send the message or the information and then we release the connection. Connection-oriented service is more reliable than connectionless service. We can send the message in a connection-oriented service if there is an error at the receiver's end. An example of connection-oriented is TCP (Transmission Control Protocol) protocol. In the above diagram, a solid line between Device A and Device B indicates that there is a dedicated link with which the stream of data travels between them. With the help of this link, a receiver can send an acknowledgment to the sender about the status of the packet. Advantages Benefits of Connection-Oriented Services are as follows:  Connection-Oriented Services are reliable. There is no duplication of data packets. There are no chances of Congestion. These are Suitable for long connections. Sequencing of data packets is guaranteed. Disadvantages Drawbacks of Connection-Oriented Service are as follows: This allocation of resources is mandatory before communication. The speed of connection is slower. As much time is taken for establishing and relinquishing the connection. In the case of Network Congestion or router failures, there are no alternative ways to continue with communication. Connection Less Services It is similar to the postal services, as it carries the full address where the message (letter) is to be carried. Each message is routed independently from source to destination. The order of messages sent can be different from the order received. In connectionless the data is transferred in one direction from source to destination without checking the destination is still there or not or if it prepared to accept the message. Authentication is not needed in this. An example of a Connectionless service is UDP (User Datagram Protocol) protocol. Advantages Benefits of Connection Less Services are as follows: There are usually low overheads.  Connection-Oriented services help to broadcast or multicast messages to multiple recipients. In this, there is no circuit setup. Thus it takes a fraction of a minute in order to establish a connection. In the case of Network congestion or router failures, it has an alternative path of data transmission. Disadvantages Drawbacks of Connection fewer services are as follows: These are susceptible to congestion in the network. It is not reliable as there is the possibility of a loss of data packets, wrong delivery of packets or duplication is high. In this, each data packet needs lengthy fields because these are supposed to hold all the destination addresses and the routing information. Let us understand the differences between the above given two services: IP Address classes An Internet Protocol (IP) address is the unique identifying number assigned to every device connected to the internet. An IP address definition is a numeric label assigned to devices that use the internet to communicate. Computers that communicate over the internet or via local networks share information to a specific location using IP addresses. P addresses have two distinct versions or standards. The Internet Protocol version 4 (IPv4) address is the older of the two, which has space for up to 4 billion IP addresses and is assigned to all computers. The more recent Internet Protocol version 6 (IPv6) has space for trillions of IP addresses, which accounts for the new breed of devices in addition to computers. There are also several types of IP addresses, including public, private, static, and dynamic IP addresses.  Every device with an internet connection has an IP address, whether it’s a computer, laptop, IoT device, or even toys. The IP addresses allow for the efficient transfer of data between two connected devices, allowing machines on different networks to talk to each other. The working of an IP address follows a set of rules to send information. Using these rules and protocols, we can send, and receive data to and from the connected devices. The steps are as follows: First, your device requests the Internet Service Provider for access to the web, which it further grants. Second, an IP address is assigned to your device from the given available range. Third, your internet activity goes via the service provider, and they route it to you using the IP address you got. Then, furthermore, your IP address can change. For example, if you turn off and on your router, your IP address can change. It also changes if you change the network of your device. IP Address Classes IPv4 addresses are divided into five classes: A, B, C, D, and E. These classes were designed to accommodate different network sizes and use cases. 1.Class A: Large networks with a vast number of devices. The first 8 bits represent the network, and the remaining 24 bits are for host addresses. Class A has range from 0 to 126 like (125.255.23.17) 2.Class B: Medium-sized networks. The first 16 bits represent the network, and the remaining 16 bits are for host addresses. Class B has range from 128 to 191 like (190.23.28.144) 3.Class C: Small networks. The first 24 bits represent the network, and the remaining 8 bits are for host addresses. Class C has range from 192 to 223 like (192.204.18.114) 4.Class D: Used for multicast addressing, which allows a single data packet to be transmitted to multiple devices simultaneously. Class D has range from 224 to 239 like (used for multicasting) 5.Class E: Reserved for experimental purposes and future use. Class E has range from 240 to 255 like (Used for research) Some use cases with examples of IP address classes are:- Class A: Large enterprises, government organizations, and ISPs typically use Class A IP addresses to accommodate a vast number of devices. Class B: Universities, large schools, and mid-sized companies often use Class B IP addresses. Class C: Small businesses, home networks, and small organizations generally use Class C IP addresses. Class D: Class D IP addresses are used for multicast addressing in applications such as video conferencing and IPTV. IPV4 VS IPV6 Sr. IPV4 IPV6 no 1 IPv4 IPv6 has a 128-bit address length has a 32-bit addre ss length 2 Address Address representation of IPv6 is in representation hexadecimal  of IPv4 is in decimal 3 IPv4’s IP IPv6 does not have any classes of the IP addresses are address. divided into five different classes. Class A , Class B, Class C, Class D , Class E. 4 Example of Example of IPv6: IPv4: 66.94.29. 2001:0000:3238:DFE1:0063:0000:0000:FEF 13 B 5 The range of The range of IPV6 address is 0 to IPV4 address 65535 is of 0 to 255 6 It consist 4 It consist 8 octets each has 16 bits octets each has 8 bits 7 IPV4 is a IPV6 is a alphanumeric number numeric separated by colon(:) address separated by (.) dot 8 IPv4 has a limited IPv6 has a large number of IP addresses. number of IP addresses. 9 It generates 4 billion unique It generates 340 undecillion unique addresses. addresses 10 It does not It provides encryption and provide authentication. encryption and authenticatio n.