Casting & Network Topology

Casting: Transmitting the data in the form of packets over the internet is called casting.

Types of Castings

The different types of casting are as follows −
Unicast − Transmitting data from one host to another host (one-one)
Broad cast − Transmitting data from one host to many host (one-all)
Multicast − Transmitting data from one host to a particular group of host (one-many).

Unicast
Transmitting data from one source host to one destination host is called a unicast. It is called as a one to one transmission.

For example − source Host IP Address 192.168.20.1 sending data to destination Host having IP Address 192.122.140.34

Packet = Data + Source Host IP + Destination Host IP

                              192.168.20.1      192.122.140.34

Broadcast
Transmitting data from one source host to all other hosts present in the same or other network is called broadcast. It is called a one to all transmission.

Broadcast is classified into two types, which are as follows −
Limited Broadcast − Transmitting data from one source host to all other hosts present in the same network is called a limited broadcast.

In Limited Broad casting if the destination address is 255.255.255.255 then the packet will be sent to all the hosts in the network.
Limited Broadcast address of any network
=255.255.255.255
= 11111111.11111111.11111111.11111111
For example − If the source IP address is 11.1.2.3 sending data to all other hosts present in the same network, then the destination address is 255.255.255.255.

Packet = Data + Source Host IP + Destination Host IP
                                 11.1.2.3              255.255.255.255

Direct Broadcast − Transmitting data from source host to all other hosts present in different networks then it is called as direct broadcast.

In direct broadcast Host ID bits are all set to 1, Network ID is the IP address where all destination hosts are present.
For example − Source IP address is 11.1.2.3  sending data to all other nodes present at different network having IP address 24.0.0.0
Therefore source address= 11.1.2.3
Destination address= 24.255.255.255

Packet = Data + Source Host IP + Destination Host IP
                                 11.1.2.3            24.255.255.255
Multicast
Transmitting data from one source host to a particular group of hosts that are interested in receiving the data is called Multicast. It is also called one to many transmissions.

For example − Sending messages on whatsapp to particular groups, video conferences, and sending email to groups of people.

Network topology:

Network topology is the layout of a network. It consists of two parts; 

physical and logical. 

The physical part describes the physical layout of a network while the logical part describes how the data flows in that network. 

Both, physical and logical parts are also known as the physical topology and the logical topology.

Physical part (topology) + Logical part (topology) = Network topology

Types Of Network Topologies:

BUS Topology

Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology.

    

When a computer transmits data in this topology, all computers see that data over the wire, but only that computer accepts the data to which it is addressed. It is just like an announcement that is heard by all but answered only by the person to whom the announcement is made.

For example, if in the above network, PC-A sends data to the PC-C then all computers of the network receive this data but only the PC-C accepts it. The following image shows this process.

  

If PC-C replies, only the PC-A accepts the return data. The following image shows this process.

Features of Bus Topology

1.It transmits data only in one direction.

2.Every device is connected to a single cable

Advantages of Bus Topology

1.It is cost effective.

2.Cable required is least compared to other network topology.

3.Used in small networks.

4.It is easy to understand.

5.Easy to expand joining two cables together.

Disadvantages of Bus Topology

1.Cables fails then whole network fails.

2.If network traffic is heavy or nodes are more the performance of the network decreases.

3.Cable has a limited length.

4.It is slower than the ring topology.

RING Topology

It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.

                            

Features of Ring Topology

1.A number of repeaters are used for Ring topology with large number of nodes, because if someone wants to send some data to the last node in the ring topology with 100 nodes, then the data will have to pass through 99 nodes to reach the 100th node. Hence to prevent data loss repeaters are used in the network.

2.The transmission is unidirectional, but it can be made bidirectional by having 2 connections between each Network Node, it is called Dual Ring Topology.

3.In Dual Ring Topology, two ring networks are formed, and data flow is in opposite direction in them. Also, if one ring fails, the second ring can act as a backup, to keep the network up.

4.Data is transferred in a sequential manner that is bit by bit. Data transmitted, has to pass through each node of-hg  the network, till the destination node.

Advantages of Ring Topology

1.Transmitting network is not affected by high traffic or by adding more nodes, as only the nodes having tokens can transmit data.

2.Cheap to install and expand

Disadvantages of Ring Topology

1.Troubleshooting is difficult in ring topology.

2.Adding or deleting the computers disturbs the network activity.

3.Failure of one computer disturbs the whole network.

STAR Topology

In this topology, all computers connect to a centralized networking device. Usually, a networking switch or a Hub (in earlier days) is used as the centralized device. Each computer in the network uses its own separate twisted pair cable to connect to the switch. Twisted pair cable uses RJ-45 connectors on both ends.

The following image shows an example of the star topology.

                                        

To transmit data, the star topology uses the same concept which the bus topology uses. It means, if you build a network using the star topology, then that network will use the bus topology to transmit the data.

Features of Star Topology

1.Every node has its own dedicated connection to the hub.

2.Hub acts as a repeater for data flow.

3.Can be used with twisted pair, Optical Fibre or coaxial cable.

Advantages of Star Topology

1.Fast performance with few nodes and low network traffic.

2.Hub can be upgraded easily.

3.Easy to troubleshoot.                                                                              

4.Easy to setup and modify.                                                                       

5.Only that node is affected which has failed, rest of the nodes can work smoothly.

Disadvantages of Star Topology

1.Cost of installation is high.

2.Expensive to use.

3.If the hub fails then the whole network is stopped because all the nodes depend on the hub.

4.Performance is based on the hub that is it depends on its capacity

MESH Topology

It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Mesh has n(n-1)/2 physical channels to link n devices.

                           

Required connections = n * (n-1)/2

Here, n is the number of end devices or locations.

For example, to make a fully meshed network of 4 end devices, we need 4*(4-1)/2 = 6 connections.

There are two techniques to transmit data over the Mesh topology, they are :

1.Routing

2.Flooding

MESH Topology: Routing

In routing, the nodes have a routing logic, as per the network requirements. Like routing logic to direct the data to reach the destination using the shortest distance. Or, routing logic which has information about the broken links, and it avoids those node etc. We can even have routing logic, to re-configure the failed nodes.

MESH Topology: Flooding

In flooding, the same data is transmitted to all the network nodes, hence no routing logic is required. The network is robust, and the its very unlikely to lose the data. But it leads to unwanted load over the network.

 

Types of Mesh Topology

1.Partial Mesh Topology : In this topology some of the systems are connected in the same fashion as mesh topology but some devices are only connected to two or three devices.

2.Full Mesh Topology : Each and every nodes or devices are connected to each other.

Features of Mesh Topology

1.Fully connected.

2.Robust.

3.Not flexible.

Advantages of Mesh Topology

1.Each connection can carry its own data load.

2.It is robust.

3.Fault is diagnosed easily.

4.Provides security and privacy.

Disadvantages of Mesh Topology

1.Installation and configuration is difficult.

2.Cabling cost is more.

3.Bulk wiring is required.

TREE Topology

It has a root node and all other nodes are connected to it forming a hierarchy. It is also called hierarchical topology. It should at least have three levels to the hierarchy.

                         

Features of Tree Topology

1.Ideal if workstations are located in groups.

2.Used in Wide Area Network.

Advantages of Tree Topology

1.Extension of bus and star topologies.

2.Expansion of nodes is possible and easy.

3.Easily managed and maintained.

4.Error detection is easily done.

Disadvantages of Tree Topology

1.Heavily cabled.

2.Costly.

3.If more nodes are added maintenance is difficult.

4.Central hub fails, network fails.

HYBRID Topology

This topology is a mix of two or more topologies. For example, there are two networks; one is built from the star topology and another is built from the bus topology. If we connect both networks to build a single large network, the topology of the new network will be known as the hybrid topology.

You are not restricted to the bus and star topologies. You can combine any topology with another topology. In modern network implementations, the hybrid topology is mostly used to mix the wired network with the wireless network.

The following image shows an example of the hybrid network topology.

  

Features of Hybrid Topology

•It is a combination of two or topologies

•Inherits the advantages and disadvantages of the topologies included

Advantages of Hybrid Topology

•Reliable as Error detecting and trouble shooting is easy.

•Effective.

•Scalable as size can be increased easily.

•Flexible.

Disadvantages of Hybrid Topology

•Complex in design.

•Costly

Line Configuration in Computer Networks

Line Configuration in Computer Networks

A Network is nothing but a connection made through connection links between two or more devices. Devices can be a computer, printer or any other device that is capable to send and receive data. There are two ways to connect the devices :
1.Point-to-Point connection
2.Multipoint connection

Point-To-Point Connection

It is a protocol which is used as a communication link between two devices. It is simple to establish. The most common example for Point-to-Point connection (PPP) is a computer connected by telephone line. We can connect the two devices by means of a pair of wires or using a microwave or satellite link.

Example: Point-to-Point connection between remote control and Television for changing the channels.

  

MultiPoint Connection

It is also called Multidrop configuration. In this connection two or more devices share a single link.

There are two kinds of Multipoint Connections :

If the links are used simultaneously between many devices, then it is spatially shared line configuration.

If user takes turns while using the link, then it is time shared (temporal) line configuration.

 

Network Devices

Network devices are physical hardware components that link computers, printers, fax machines, and other electronic devices to a network. These devices quickly, securely, and accurately transfer data over the same or separate networks. Network equipment can be either intra or inter-networked. 

A NIC card or RJ45 connection is an installed device, whereas a router, switch, or another network device is a network component. 

Modem

A computer may send and receive data through phone or cable lines with the help of a modem. In contrast to a telephone line or cable wire, which can only carry analog data, the data saved on a computer is digital.

The modem’s primary job is to transform digital signals between analog and digital and vice versa. Combining a modulator and a demodulator creates a modem. When digital data is sent by the computer, the modulator turns it into analog data. When analog data signals are received by the computer, they are demodulated into digital data.

Types of Modem

There are several different types of modems depending on the direction of data transmission:

Simplex − Using a simplex modem, data can only be transferred from a digital device to a network (modulator) or from a network to a digital device in one direction (demodulator).

Half duplex − While a half-duplex modem can transport data in both ways, it can do so only in one direction at a time.

Full duplex − A full duplex modem may simultaneously send data in both directions.

Hub:

Hubs work in the physical layer of the OSI model. A hub is a device for connecting multiple Ethernet devices and making them act as a single network segment. It has multiple inputs and output ports in which a signal introduced at the input of any port appears at the output of every port except the original incoming port.

A hub can be used with both digital and analog data. Hubs do not perform packet filtering or addressing function, they send the data packets to all the connected devices.

Demonstrate the functionality of a hub using Cisco Packet Tracer (CPT)

1. Open Cisco Packet Tracer

Launch Cisco Packet Tracer on your computer.

2. Create a New Project

Go to File > New to start a new project.

3. Add Devices to Your Workspace

From the bottom device toolbar, choose the following devices:

Hub: You can find this under the Network Devices tab > Hubs.

PCs: Select End Devices > PC.

Drag and drop one Hub and at least two PCs onto the workspace.

4. Connect the Devices

Choose the Connections icon (it looks like a lightning bolt).

Select the Copper Straight-Through cable.

5. Click on the first PC, choose the FastEthernet0 interface.

Connect it to one of the ports on the Hub.

Repeat this process for the second PC, connecting it to a different port on the Hub.

6. Configure IP Addresses for the PCs

Click on the first PC and then on the Desktop tab.

Select IP Configuration.

Assign an IP address and subnet mask (e.g., IP: 192.168.1.1, Subnet Mask: 255.255.255.0).

Repeat this for the second PC, assigning a different IP address but the same subnet mask (e.g., IP: 192.168.1.2, Subnet Mask: 255.255.255.0).

7. Verify Connectivity

On the first PC, go to Command Prompt under the Desktop tab.

Type ping 192.168.1.2 and press Enter.

You should see replies from the second PC if everything is set up correctly.

8. Observe the Hub’s Operation

To observe how the hub works, click on the Hub.

Go to the Physical tab and then select Power to turn it on.

Note that a hub is a Layer 1 device and doesn’t have advanced configuration options. It simply forwards packets to all connected devices.

9. Use Simulation Mode for Detailed Analysis

Switch to Simulation Mode by clicking the Simulation tab.

Set up a simple Ping simulation by adding an Event to the network.

Observe how the hub broadcasts the frame to all ports and how only the intended recipient responds.

10. Verify Frames Being Broadcast

In Simulation Mode, add the PCs and use the Add Simple PDU tool to send a message from one PC to another.

Watch how the hub sends the frame out of all ports, but only the destination PC will respond.

11. Save Your Project

Go to File > Save and choose a location to save your Packet Tracer file for future reference.

Repeater:

A repeater operates at the physical layer of the OSI model.A Repeater connects two segments of a network cable.Sometimes it regenerates the signals to proper amplitudes and sends them to the other segment.If the signal becomes weak, it can copy the signal bit by bit and regenerate it at the original strength.It is a 2-port device.

Demonstrate the functionality of a Repeater using Cisco Packet Tracer (CPT):

A repeater is used to extend the range of a network by amplifying signals, so this exercise will help you understand how a repeater works to maintain connectivity over greater distances.

1. Open Cisco Packet Tracer

Launch Cisco Packet Tracer on your computer.

2. Create a New Project

Go to File > New to start a new project.

3. Add Devices to Your Workspace

From the bottom device toolbar, choose the following devices:

Repeater: You can find this under the Network Devices tab > Hubs.

PCs: Select End Devices > PC.

Drag and drop one Repeater and at least two PCs onto the workspace.

4. Connect the Devices

Choose the Connections icon (it looks like a lightning bolt).

Select the Copper Straight-Through cable.

Connect one PC to the first port of the Repeater.

Connect the Repeater’s second port to another PC.

Note: Ensure the distance between the PCs is sufficient to show the benefit of the repeater. You may want to place the repeater in between to visually represent its function.

5. Configure IP Addresses for the PCs

Click on the first PC and then on the Desktop tab.

Select IP Configuration.

Assign an IP address and subnet mask (e.g., IP: 192.168.1.1, Subnet Mask: 255.255.255.0).

Repeat this for the second PC, assigning a different IP address but the same subnet mask (e.g., IP: 192.168.1.2, Subnet Mask: 255.255.255.0).

6. Verify Connectivity

On the first PC, go to Command Prompt under the Desktop tab.

Type ping 192.168.1.2 and press Enter.

You should see replies from the second PC if everything is set up correctly.

7. Observe the Repeater’s Operation

To observe the repeater's operation, you can use the Physical tab to view the repeater's connections and ensure it’s powered on.

The repeater doesn’t have advanced settings; it simply forwards electrical signals to extend the network range.

8. Use Simulation Mode for Detailed Analysis

Switch to Simulation Mode by clicking the Simulation tab.

Set up a simple Ping simulation by adding an Event to the network.

Observe how the signal from one PC travels through the repeater to the other PC.

9. Verify Signal Transmission

In Simulation Mode, add the PCs and use the Add Simple PDU tool to send a message from one PC to another.

Watch how the repeater amplifies the signal to ensure it reaches the other PC.

10. Save Your Project

Go to File > Save and choose a location to save your Packet Tracer file for future reference.

Switch

Switches may operate at one or more layers of the OSI model. They may operate in the data link layer and network layer; a device that operates simultaneously at more than one of these layers is known as a multilayer switch.

A Switch can check the errors before forwarding the data, which makes it more efficient and improves its performance. A switch is the better version of a hub. It is a multi-port bridge device.

Demonstrate the functionality of a switch using Cisco Packet Tracer (CPT): Fundamental role of a switch in forwarding traffic efficiently within a network. Here’s a step-by-step guide to illustrate the operation of a switch:

1. Open Cisco Packet Tracer

Launch Cisco Packet Tracer on your computer.

2. Create a New Project

Go to File > New to start a new project.

3. Add Devices to Your Workspace

From the bottom device toolbar, choose the following devices:

Switch: You can find this under the Network Devices tab > Switches.

PCs: Select End Devices > PC.

Drag and drop one Switch and at least two PCs onto the workspace.

4. Connect the Devices

Choose the Connections icon (it looks like a lightning bolt).

Select the Copper Straight-Through cable.

Connect one PC to one of the ports on the Switch.

Connect the second PC to another port on the Switch.

Repeat this process if you want to add more PCs to the Switch.

5. Configure IP Addresses for the PCs

Click on the first PC and then on the Desktop tab.

Select IP Configuration.

Assign an IP address and subnet mask (e.g., IP: 192.168.1.1, Subnet Mask: 255.255.255.0).

Repeat this for the second PC, assigning a different IP address but within the same subnet (e.g., IP: 192.168.1.2, Subnet Mask: 255.255.255.0).

6. Verify Connectivity

On the first PC, go to Command Prompt under the Desktop tab.

Type ping 192.168.1.2 and press Enter.

You should see replies from the second PC if everything is set up correctly.

7. Observe the Switch’s Operation

To observe the switch’s operation, click on the Switch.

Go to the CLI tab to access the command-line interface.

Use basic commands like show mac address-table to view the MAC address table of the switch.

Example CLI Commands:

show mac address-table: Displays the MAC address table, showing which MAC addresses are associated with which switch ports.

commands to show MAC address using CLI

Switch>enable

Switch#show mac-address-table 

          Mac Address Table

-------------------------------------------

Vlan    Mac Address       Type        Ports

----    -----------       --------    -----

   1    0000.0cc0.6a7d    DYNAMIC     Fa0/2

   1    0002.4ab0.2786    DYNAMIC     Fa0/1

   1    0004.9ab0.85da    DYNAMIC     Fa0/3

8. Use Simulation Mode for Detailed Analysis

Switch to Simulation Mode by clicking the Simulation tab.

Add a simple Ping simulation by using the Add Simple PDU tool to send a message from one PC to another.

Observe how the switch learns the MAC addresses and forwards the frame only to the port where the destination PC is connected.

9. Verify Frame Forwarding

In Simulation Mode, observe how the switch uses its MAC address table to forward the frame from one PC to another.

Note that the switch only sends the frame to the port associated with the destination MAC address, unlike a hub, which would broadcast the frame to all ports.

10. Save Your Project

Go to File > Save and choose a location to save your Packet Tracer file for future reference.

Bridge

A bridge operates at the data link layer of the OSI model. It can read only the outmost hardware address of the packet but cannot read the IP address. It reads the outmost section of the data packet to tell where the message is going. It reduces the traffic on other network segments. It does not send all the packets. So, a bridge can be programmed to reject packets from a particular network.

Note:

1. Bridge is a layer 2 device which is used to connect the same protocols used for  2 different  LANS

2. Router is a layer 3 device which is used to connect the Different protocols used for 2 different  LANS

Steps to Observe MAC Address Functionality:

Setup a Simple Network:

Create a basic network topology with devices such as PCs, switches (bridges), and routers.

For example, connect two PCs (PC1 and PC2) to a switch.

Configure IP Addresses:

Assign IP addresses to the PCs to ensure they can communicate with each other.

E.g., assign 192.168.1.1/24 to PC1 and 192.168.1.2/24 to PC2.

Access the Switch (Bridge):

Click on the switch in the Packet Tracer workspace to open the switch's configuration menu.

Access the CLI (Command Line Interface) of the switch.

Send Traffic Between PCs:

Use one of the PCs (e.g., PC1) to send a ping to the other PC (e.g., PC2).

This will generate traffic that the switch needs to forward, prompting it to learn the MAC addresses.

View the MAC Address Table:

On the switch's CLI, enter the command show mac address-table or show mac-address-table.

This command will display the MAC addresses that the switch has learned and the corresponding ports.

Switch> enable

Switch# show mac-address-table

Analyze the MAC Address Table:

The MAC address table will show you the MAC addresses of the devices connected to the switch and the port numbers they are associated with.

Each entry in the MAC address table indicates that the switch has learned the MAC address of a device on a specific port.

Router

Routers are small physical devices that operate at the network layer to join multiple networks together.A router is a device like a switch that routes data packets based on their IP addresses.

Routers normally connect LANs and WANs and have a dynamically updating routing table based on which they make decisions on routing the data packets.

A Router divides the broadcast domains of hosts connected through it.

Routers perform the traffic directing functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination code.

Routers may also be used to connect two or more logical groups of computer devices known as subnets, each with a different subnetwork address. The subnet addresses recorded in a router do not necessarily map directly to the physical interface connections.

Demonstrate the functionality of a Router using Cisco Packet Tracer (CPT):

1: Setup the Network Topology

Open Cisco Packet Tracer.

Add Devices to the Workspace:

Drag and drop the following devices onto the workspace:

1 Router (e.g., Router0)

2 Switches (e.g., Switch0, Switch1)

4 PCs (e.g., PC0, PC1, PC2, PC3)

Connect Devices:

Use the Copper Straight-Through cable to connect:

PC0 to Switch0

PC1 to Switch0

PC2 to Switch1

PC3 to Switch1

Use the Copper Straight-Through cable to connect:

Switch0 to Router0 on the GigabitEthernet 0/0 interface

Switch1 to Router0 on the GigabitEthernet 0/1 interface

2: Configure IP Addresses on PCs

Configure PC0 and PC1 (Subnet 1):

Click on PC0, go to the Desktop tab, and select IP Configuration.

Assign the following IP details:

IP Address: 192.168.1.2

Subnet Mask: 255.255.255.0

Default Gateway: 192.168.1.1

Repeat the same for PC1, but with an IP Address of 192.168.1.3.

Configure PC2 and PC3 (Subnet 2):

Click on PC2, go to the Desktop tab, and select IP Configuration.

Assign the following IP details:

IP Address: 192.168.2.2

Subnet Mask: 255.255.255.0

Default Gateway: 192.168.2.1

Repeat the same for PC3, but with an IP Address of 192.168.2.3.

3: Configure IP Addresses on Router Interfaces

Access Router CLI:

Click on the Router0 and go to the CLI tab.

Configure Router Interfaces:

Enter the following commands to configure the IP addresses for the router’s interfaces:

shell

Copy code

Router> enable

Router# configure terminal

Router(config)# interface gigabitEthernet 0/0

Router(config-if)# ip address 192.168.1.1 255.255.255.0

Router(config-if)# no shutdown

Router(config-if)# exit

Router(config)# interface gigabitEthernet 0/1

Router(config-if)# ip address 192.168.2.1 255.255.255.0

Router(config-if)# no shutdown

Router(config-if)# exit

Router(config)# end

Router# write memory

This sets up the router to be in the same subnet as the PCs on their respective networks.

4: Test Connectivity Between PCs

Ping within the Same Subnet:

Go to PC0, open the Command Prompt, and type the following command:

shell

Copy code

ping 192.168.1.3

This tests connectivity between PC0 and PC1 on the same subnet.

Ping Across Different Subnets:

From PC0, ping PC2 using the command:

shell

Copy code

ping 192.168.2.2

If successful, this shows that the router is correctly routing packets between different subnets.

Two types of routers −

Static routers – Static routers are configured manually and route data packets based on the information in a router table.

Dynamic routers – Dynamic routers use adaptive routing which is a process where a router can forward data by a different route

Gateway

A gateway is an internetworking capable of joining together two networks that use different base protocols.

A network gateway can be implemented completely in software, hardware, or a combination of both, depending on the types of protocols they support.

A network gateway can operate at any level of the OSI model. A broadband router typically serves as the network gateway, although ordinary computers can also be configured to perform equivalent functions.

A gateway is a router or proxy server that routes between networks.

A gateway belongs to the same subnet to which the PC belongs.

Steps to Configure and Use a Gateway in Cisco Packet Tracer

Create a Basic Network Topology:

Place at least one PC, one switch, and one router on the workspace.

Connect the PC to the switch using a copper straight-through cable.

Connect the switch to the router using another copper straight-through cable.

Assign IP Addresses:

Assign an IP address to the PC.

Click on the PC, go to the Desktop tab, and select IP Configuration.

Assign an IP address (e.g., 192.168.1.2) and a subnet mask (e.g., 255.255.255.0).

Set the default gateway to the router's IP address on the same network (e.g., 192.168.1.1).

Configure the router's interface:

Click on the router, go to the CLI or Config tab.

Select the interface connected to the switch (e.g., GigabitEthernet0/0).

Assign an IP address (e.g., 192.168.1.1) and subnet mask (255.255.255.0) to the router's interface.

Enable the interface with the no shutdown command if using the CLI.

Example configuration for the router:

Router> enable

Router# configure terminal

Router(config)# interface GigabitEthernet0/0

Router(config-if)# ip address 192.168.1.1 255.255.255.0

Router(config-if)# no shutdown

Configure the PC's Default Gateway:

The PC's default gateway should be the IP address of the router's interface connected to the switch (e.g., 192.168.1.1).

This tells the PC where to send packets destined for outside the local network.

Test Connectivity:

You can test connectivity by pinging the router's IP address from the PC.

Open the command prompt on the PC (Desktop > Command Prompt) and type:

ping 192.168.1.1

If everything is configured correctly, you should receive replies, indicating that the PC can communicate with the router (gateway).

Routing Beyond the Gateway (Optional):

If your router is connected to another network (e.g., a simulated internet), you can configure routing on the router to forward traffic to that network.

For example, you can set up a static route or use a dynamic routing protocol to enable communication between different networks.

ARPANET

Network Topology:

Network topology is the layout of a network. It consists of two parts; physical and logical. The physical part describes the physical layout of a network while the logical part describes how the data flows in that network. Both, physical and logical parts are also known as the physical topology and the logical topology.

Physical part (Topology) + Logical part (Topology) = Network Topology

History of Computer Networking:

A computer network is a group of computers that has the potential to transmit, receive and exchange voice, data, and video traffic. 

The network and data communication are the essential factors to rise information technology in the world as technology's advancement is on the system, including the gadgets. ARPANET began the networking long ago.

In 1957, when SPUTNIK Satellite was launched by Russia. An agency named ADVANCED RESEARCH PROJECT AGENCY (ARPA) was started by American, and its first satellite was launched within 18 months after establishment. Then they used ARPANET to share the information on another computer. America's Dr. LIED LIEDER has this all responsibility. Then, ARPANET came to India in 1969, and its name changed from Indian to NETWORK.

For the United States Department of Defense, the funding of the design of the Advanced Research Projects Agency Network (ARPANET) was began by ARPA. In 1969, the network began to develop on the basis of the developed designs in the 1960s. The below table contains a complete history of computer networking:

Year	Event
1961	In this year, Leonard Kleinrock proposed the earliest computer networks, which was the idea of ARPANET.
1965	In 1965, Donald Davies coined the term "packet" to describe how to send data between computers on a network.
1969	Although In 1966, the development of ARPANET began, officially started ARPANET in 1969. It was considered one of the first computer networks in which first two nodes, UCLA and SRI (Stanford Research Institute) were connected, and to use packet switching. To provide and define information about network protocols, procedures, and computer communications, the first RFC surfaced as a document in April 1969.
1969	On 29 August 1969, the first IMP and network switch were sent to UCLA. On ARPANET, the first data transmission was sent by using it.
1970	NCP, stands for NetWare Core Protocol, released by Steve Crocker and a team at UCLA for use with NetWare.
1971	In 1971, the first e-mail was sent to across a network to other users by Ray Tomlinson.
1973	While working at Xerox PARC, Robert Metcalfe developed the Ethernet in 1973. In the same year, ARPA deployed the first international network connection, known as SATNET. In 1973, VoIP technology and capabilities were officially introduced, which made a VoIP call. However, until 1995, the software was not available for users that could make VoIP calls.
1974	In this year, the use of first router was began, but they were not considered true IP routers.
1976	Originally called a gateway, Ginny Strazisar develop the first true IP router.
1978	In 1978, the TCP/IP protocol was developed and invented by Bob Kahn for networks; it was developed with help from Vint Cerf.
1981	In the United States, between IBM mainframe systems, BITNET was created in 1981 as a network. The U.S. National Science Foundation developed the CSNET (Computer Science Network) in the same year 1981.
1983	For using TCP/IP, ARPANET finished the transition. The first DNS implement by Jon Postel and Paul Mockapetris in 1983.
1986	This is the year in which a backbone for ARPANET, the National Science Foundation Network was came online, which finally took the place of ARPANET in 1990s. In the same year, with the original BITNET, BITNET II was introduced to deal with bandwidth issues.
1988	In 1988, the first T1 backbone was included with ARPANET. AT&T, Lucent, and NCR introduced the WaveLAN network technology in 1988. In 1988, for the first time, the explanation of network firewall technology was published. In the same year, Digital Equipment Corporation developed it. This paper had the detail about the first firewall, known as a packet filter firewall.
1990	The first network switch was developed and introduced by a U.S. network hardware company named Kalpana in 1990.
1996	In 1996, an IPv6 was introduced as an improvement over IPv4, as well as embedded encryption, improved routing.
1997	In June 1997, the 802.11 standards, containing transmission speeds up to 2 Mbps, for Wi-Fi were introduced.
1999	The 802.11a standard, containing transmission speeds up to 25 Mbps to use the 5 GHz band, was officially made in 1999. Another standard 802.11b was available to use for the public in mid-1999, which offered transmission speeds up to 11 Mbps. In September 1999, for use with 802.11b, the WEP encryption protocol was released.
2003	802.11g devices, contained transmission speeds up to 20 Mbps, were available to the public in January 2003. In the same year, for use with 802.11g, the WPA encryption protocol is released.
2004	In 2004, as a replacement for WPA, the WPA2 encryption protocol was introduced. By 2006, WPA2 certification was compulsory for all Wi-Fi devices.
2009	The 802.11n standard can operate on the 2.4 GHz and 5 GHz bandwidths and offers higher transfer speeds over 802.11a and 802.11g. Officially, it was made in 2009.
2018	In January 2018, WPA3 encryption was released by the Wi-Fi Alliance, which comprises security enhancements over WPA2.