Download free courses materials, tutorials training on computer hardware in PDF Description: Download free Computer Network course material and tutorial. Mar 31, “No man but a blockhead ever wrote, except for money.” - Samuel Johnson. The textbook world is changing. On the one hand, open source. Describe the functionality of LAN, MAN, and WAN networks. • Identify the possible . MAC Address. • The network interface card address, called the hardware.
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Tools for teaching computer networking and hardware concepts / Nurul Sarkar, editor. Chapter IX provides a tutorial on Wi-Fi networking and radio propaga-. In this chapter, you'll begin by relating networks to situations and concepts hardware or software failure that causes information or applications to be. Networking concepts and hardware. Basic Communications Model Standards are needed at all Layers. User Layer. Application Layer. Computer (Transport).
The network hardware, connectors, cable, and NICs may require some maintenance. Connector problems are the most common, then cable problems, and finally defective NICs. Checking Connectors Cable connectors are the weakest link in the network hardware chain. Because of this, you should check the connectors first when your computers can't communicate. If you wired your network with Cat-5 twisted-pair cable, you should check the following: See if the connectors are properly inserted in the NICs. Make sure that the connectors are properly inserted in the concentrator hub, switch, or router. Be sure that the concentrator is plugged in.
IP Internet Protocol : It is responsible for addressing, sending and receiving the data packets over the internet. When we type something in an address bar, our request will be processed to the server. The server will respond back to us with the request. The messages are sent and received in small packages. This layer includes two activities Transmitting data to the Network Interface layers Routing the data to the correct destinations So how this happen? Internet layer packs data into data packets referred as IP datagrams.
It consists of source and destination IP address. Beside this, IP datagram header field consists of information like version, header length, type of service, datagram length, time to live, and so on.
The datagram are transported through network using these protocols. They each resemble some function like. It determines how to route message on the network. Likewise, you will have ICMP protocol. It is responsible for diagnostic functions and reporting errors due to the unsuccessful delivery of IP packets. The ARP or Address Resolution Protocol is responsible for the resolution of the Internet layer address to the Network Interface layer address such as a hardware address. The image below shows the format of an IP address.
It is responsible for providing the Application layer with session and datagram communication services. TCP is responsible for the sequencing, and acknowledgment of a packet sent. It also does the recovery of packet lost during transmission. Packet delivery through TCP is more safe and guaranteed. UDP is used when the amount of data to be transferred is small.
It does not guarantee packet delivery. Network Segmentation Network segmentation implicates splitting the network into smaller networks. It helps to split the traffic loads and improve the speed of the Internet. Network Segmentation can be achieved by following ways, By implementing DMZ demilitarised zones and gateways between networks or system with different security requirements. By implementing DSD evaluated cross-domain solutions where necessary Why Network Segmentation is important Network Segmentation is important for following reasons, Improve Security- To protect against malicious cyber attacks that can compromise your network usability.
To detect and respond to an unknown intrusion in the network Isolate network problem- Provide a quick way to isolate a compromised device from the rest of your network in case of intrusion. Segmentation is done based on the factors such as project team, function or application, irrespective of the physical location of the user or device. A group of devices connected in a VLAN act as if they are on their own independent network, even if they share a common infrastructure with other VLANs.
The popular device used for segmenting are a switch, router, bridge, etc. Subnetting Subnets are more concerned about IP addresses.
Subnetting is primarily a hardware-based, unlike VLAN, which is software based. A subnet is a group of IP address. It can reach any address without using any routing device if they belong to the same subnet. Few things to consider while doing network segmentation Proper user authentication to access the secure network segment ACL or Access lists should be properly configured Access audit logs Anything that compromises the secure network segment should be checked- packets, devices, users, application, and protocols Keep watch on incoming and outgoing traffic Security policies based on user identity or application to ascertain who has access to what data, and not based on ports, IP addresses, and protocols Do not allow the exit of cardholder data to another network segment outside of PCI DSS scope.
Packet Delivery Process So far we have seen different protocols, segmentation, various communication layers, etc. Now we are going to see how the packet is delivered across the network. The process of delivering data from one host to another depends on whether or not the sending and receiving hosts are in the same domain.
A packet can be delivered in two ways, A packet destined for a remote system on a different network A packet destined for a system on the same local network If the receiving and sending devices are connected to the same broadcast domain, data can be exchanged using a switch and MAC addresses.
But if the sending and receiving devices are connected to a different broadcast domain, then the use of IP addresses and the router is required. Suppose host A wants to send a packet to host B. Since at layer 2 packets are sent with MAC address as the source and destination addresses.
Intrasegment packet routing If a packet is destined for a system on the same local network, which means if the destination node are on the same network segment of the sending node. The sending node addresses the packet in the following way.
The node number of the destination node is placed in the MAC header destination address field. The node number of the sending node is placed in the MAC header source address field The full IPX address of the destination node is placed in the IPX header destination address fields.
Layer 3 Packet delivery To deliver an IP packet across a routed network, it requires several steps. For instance, if host A wants to send a packet to host B it will send the packet in this ways Host A sends a packet to its "default gateway" default gateway router.
To send a packet to the router, host A requires to know the Mac address of the router For that Host A sends an ARP request asking for the Mac address of the Router This packet is then broadcast on the local network. Network Hub A hub connects two or more computers together like switch in diagram above. Hubs are effectively multi port repeaters and operate at the physical layer level one.
They do not examine the network traffic. They are being replaced today by the switches. Smallest is usually 4 port. Network Bridge A bridge connects two network segments together and is a selective repeater. It uses this information to decide whether or not to repeat the traffic on a network segment.
A Bridge works at level 2 data link Level and will transmit broadcasts. Bridges are also being replaced by switches Network Switch A switch Connects two or more computers together and used today in preference to a hub or bridge.
Like a bridge a switch learns about MAC address connected to each port and will only send data on that port that is addressed to those MAC addresses. A switch is effectively a bridge with more ports. Using switches usually speeds up a network but it depends on the network configuration.
See the Basic networking Course Wireless Access Point A wireless access point connects wireless devices to an Ethernet network, and to each other.
Routers A router connects networks together. Routers operate at the networking level of the TC protocol stack. On Home networks the router is responsible for connecting the home network to the Internet and provides several important networking services like: DHCP Most home routers provide both Wi-Fi and Ethernet connections.
Modern ones plug directly into a mains socket and require no other connections. Note: see Wi-Fi homeplug adapters below. You will need a Sim and a mobile data plan. They come in pairs and you need a minimum of 2 adapters.
They plug into the mains and have an Ethernet socket that you can use to connect to a computer,switch , router etc.