Ethernet
In. This section we're going to talk about Ethernet. As. We. Discussed, in our previous section. Internet, is the most widely, installed. Local, area network technology. Ethernet. Is a protocol, in describing, how, network, devices can format data for transmission, to other network, devices on the, same network segment. And how, to put data on our, network, connection. Again. As we talked before datalink, layer has, two, sub, layers and their, LLC. Logical. Link control and. Mac. Media. Access control. LLC. Organizes. Communication. With upper, lower layers and provides, common, interface, reliability. And flow control and Mac. Appends. Physical. Address to frame and provides, data encapsulation, and, error, detection. Let's. Go ahead with the collision domain. Term a collision. Domain, is a network. Segment, connected. By a shared medium. Or to, repeaters. Where data, packets, may collide, with one, another while. Being sent, a network. Collision, occurs, when, more than one device attempts. To send a packet, on a network segment, at the same time, members. Of a collision, domain, may, be involved, in collision. With one, another, guys. Only, one do I see the collision domain, may transmit, at any one, time and, the, other devices, in the domain listen. To the network and refrain. From transmitting. While, others, are already transmitting. In order to avoid. Collisions. Because. Only one device may be transmitting. At any one time total. Network bandwidth, is shared among, all devices, on, the collision, domain. Collisions. Also, decrease, the network, efficiency, on, a collision, domain, as collisions. Require devices. To abort, transmission. And retransmit. At a later, time. Religions are often, in a hub environment. Because, each, port, on a hub, is in, the same collision. Domain, by, contrast. Each, port. On a bridge, a switch. Or a rudder, is in. A separate. Collision, domain as you can see in here, we have. A switch and. This. Switch has four. Ports. Four different ports. Each. Port. Of the switch, is a, separate. Collision, domain as you can see in here this, is collision domain one this. Is collision domain, three, this. Is collision domain, - and this. Is collision domain. 4, but as you can see in here. Separate. Ports, of the hub, is not, a separate, collision, domain all, ports, of the hub are in, the same collision, domain which is collision domain 4, in here. In. A shared media, devices, may want, to send data at the same, time carrier. Sense, multiple access. CSMA, method. Is used, for sharing the, media, but, collisions. May occur, if two, devices try, to send data at the same, time on the screen as you can see that all workstations. Are saying that I send. My data, whenever, I want, and they. Don't want to share the media, so. We. Have a method, named csma. Csma/cd. CSMA, collision, detection used. For detecting, collisions, for, Ethernet. Networks. Logic. Behind this is check. Media, if, it is free sand. If not. Wait. For idle, and send, again later for. Example in here if, workstation. A wants. To communicate, with the server. It sends. A message saying. That I, need. To send something, is, there anything, currently. On the. Err not. Csma/ca. E is used, for detecting collisions, for, wireless networks, logic. Behind this, is check. Media, if, it is free. Send. A notification to, use it and then. Send. Your data, and here, how is it going on for example if the. This. Tablet. Wants. To send data to that to a wireless medium, it's checking, the data checking, the medium I'm sorry first then. It's, sending a notification to, the medium saying, that hey guys I'm gonna send the data, then. It's. Sending. Whatever. It's gonna send, and. Let's. Take a look to the ethernet, frame now in. The first fields, of Internet, we're preamble. And sft, these. Fields, provide, synchronization. Between source, and the destination devices. Secondly. We have destination. And source, address. Fields, and they. Are the source and destination MAC. Address, info. And the. Other field, is the villain, tag which, is used for quality. Of services. And carries. The villain information. That's an optional. Field and the. Other field, is length n type, which, keeps the length of data, and the type of the protocol, we are using, and the. Another field, is the data, field, which. Gives the encapsulated. Data, information, from OSI. Layer 3 and the. Last. Field. Is FCS. Frame check, sequence and. Frame, check sequence bits. Must, match for source, and destination if, no error occurred, and this, field is used for the error detection.
Let's. Take a look to the MAC, address now a media. Access control. Make. Address, of a device is a 48. Bit. Unique. Identifier. Assigned, to net, interfaces. For, communications. At the data, link, layer of, a network segment, MAC. Addresses are, used as a network. Address for. Most network technologies. Including. Ethernet. And Wi-Fi. MAC. Addresses are. Shown. In, hexadecimal. Format gasps. Hexadecimal. Is a. Position. Numeral. System, with, a radix or base, of 16. It. Uses. 16. These. Things symbols, most, often, the symbols, from. 0. To 9 to 3 present, values, from. 0, to 9, as you can see in here. And. ABCD. And, ENF. To. Represent, values from 10 to, 15. Make. Addresses, are assigned to, network devices such, as pcs. Printers. Servers. And etc, and. Consists. Of two, portions. As you can see in here the, first portion, is you I and, the second, is you AAA, or. Extended. Or device identifier. The. First portion is a UI and. Organizationally. Unique. Identifier. Or UI is. 24. Bits, number, that uniquely. Identifies a. Vendor. Manufacturer. Or other. Organization. The, second, portion is UA, or. Extended. Device identifier. This. Is a number. Unique, to the vendor, for example, let's say that this, first, portion. Is. Unique. For. For. Example maybe Intel. Maybe. Qualcomm. Then. The. MAC addresses that. Intel. Manufactures. Or kokum, manufactures. Are, finishing. With the arbitrary. Number that the, Intel. Or cool, calm says. MAC. Addresses are. Can, be represented. In three. Ways mostly, the. First, dots. Are used, between, each, four characters, as you can see as. In. Here and the. Second, dashes. Are used between each two, characters, like, here you can see as well, and in. The third double. Columns. Are, used between each two, characters. There. Are also, three. Different types. Of, internet. Addresses. And they, are unicast. Multicast. And. The, broadcast. A. Unicast. Frame, contains. The unique, MAC address of the destination receiver. And, unicast. Address, frame. Is only sent, out the. Specific. Port leading to the receiver for example, if this, computer, computer. One wants. To communicate with computer. Three over the switch and if, this is a unicast. Frame. Is going to here but, not, here and. Forwarded. To, here. A. Multicast. Frame, contains. The unique, multicast, MAC address, of an application. Protocol. Or data, stream, a multicast. Address, frame, is either fluid. At all, parts. If no. Multicast, optimization. Is configured, or sends. Out only, the ports interested. In receiving, the traffic. If you, want to send a multicast, layer to traffic, your, destination. MAC should, start, with onesy, I'm, sorry row 1 0 0 and, 5e. And. Let's. Talk about the broadcast, MAC address a broadcast. Frame, is, flooded. At all. Parts. A, broadcast. Frame contains, all binary, 1. As the, destination, address which, is F F. F F F F F F, F F and F, F, for. Example F this, guy wants. To communicate. With. All. These, other, guys. The. Source address of, the internet, frame is this, guy's MAC address and the destination gonna. Be. Here. Let's. Go ahead with the ARP. Address. Resolution. Protocol. ARP is, used. For resolution. Of IP address, into. Mac address ARP, request. Is made by. A broadcast. To F F, F F F F F F F F F, F F and our. Reply, is made, by, related. Device as unique. As for, example FPC. One, sends. An ARP, requests. The. Message, this message is broadcast. Comes. To here and comes. To here and let's. Say, that PC. One is researching, the physical, address of the station, that has the IP address. 21.3. Which, is pc 3, pc. 3 takes, this request, and replies, back, with its MAC, address, and this. Packet, is just. Sent, to, PC. 1 as unicast. Let's. Take a look to the ARP table, on networking. Devices, a table. Usually, called, ARP cache or, art table, is used, to maintain a correlation. Between each, MAC. Address and its, corresponding, IP. Address, art. Provides, the protocol, rules for making this correlation, and, providing. Address, conversion. In both, directions, in here, you are seeing an up table, of a rather and, in. Here, you are seeing an art table of a pc, the. Command. That we are using is, show IP our, command, to display the ARP, cache of. Rather and, as, you can see in here, we are seeing, the IP addresses, and they, make, addresses. Of the, same. Device, on the table. Let's. Go ahead with the land switch a local, area network switch. Is a networking, device that. Connects, devices. Together on, a computer. Network by. Using packet. Switching, to receive, process. And forward. Data to the destination. Device, switch. Mostly. Operate. At layer. 2. Of the OSI module. And provide. Switching. According. To MAC address using MAC address table on, the, local area network switch.
There's. A table called, MAC. Address table. And. What. Layer to switch is making. Is just. Switching. Between different. Ports. By using. Make. Address, information. Located, in the MAC address table. Let's. See how make addressed table is established. On a switch, right now. Firstly. The. Megara table, is empty, this, is the switch guys and MAC, address table is empty, as you can see. In. The. First step if PC, one wants. To forward, the pack up to PC to. Switch. Floods, ad out of, all, ports. And adds, PC. Ones MAC address to its. MAC, address table with. What, is going on in here is PC. One wants to communicate with PC, to, switch. Check. The frame and then. Checks the MAC address and. Immediately. Adds the PC, ones MAC. Address, to the MAC, address table and saying that hey on my first part, I have, a MAC. Address of this, bunch. To communicate, with this MAC. Address but I. Don't have this MAC address on this table so I'm, floating. The. Requests. Out from. All my. Ports. Then. Let's, say that PC 2. Sends. The eunuch has replied, to PC, 1 and switch. Adds to PC twos MAC address to make a rest able to, then. After. This process if PC one wants, to send the data to PC 2 frame. Is forwarded. Directly. In. The, end in, the, end of the day, switched. Learns all of my addresses, connected, to all of its, ports. And establish. A full. MAC address table as you can see in here and saying. That on my first part I have this, MAC address on my third, port I have this, MAC address, on, my fault, this. 7. Days, and 8, this. From. Now, on if, this. PC, 5 wants. To communicate with, PC. One frame. Is directly. Forwarded. To PC. Want, let's. Go ahead with the duplex, options. We. Have to the Plex options. Half-duplex. And, full-duplex. Half. Duplex is used, to describe, communication. Where only, one, side, can send. Data at at, time, once. One, side has finished transmitting. Its data, the. Other side can respond. Only one, node can send data at a time in half to place if both. Try to send, data at the same time a collision. Will occur in. The network. On, the, other hand, full, duplex is, used, to describe, communication. Between where. Both, sides are, able, to send, and receive data at, the same, time in, this cases there, is no danger of a collision and, therefore. The, transfer of data, is completed. Much faster. Let's go ahead with the Auto MDX. Feature in. Today's, networks, using the, proper, cable type, is very important, guys and certain. Devices has a great, feature to help us, preventing. Wrong cabling. Also. MDI. Exports. On a newer. Network, interfaces. Detect if the connection, would require, a crossover. And, automatically. Chooses. The MDI, or mdi-x. Configuration. To, properly, match the other end, of the link, and. Let's. Take a look to the frame forwarding. Types we, have three. Frame, forwarding. Types when, we are forwarding, a frame in. Our switch and they're. Thrown, forward, cut. Through and cut. Through fragment, free. Install. Forward. Method frame. Is forward. That after. The whole, frame, received. And there. Is no CRC. In. Cut row fast forward, frame. Is forwarded. After, the destination. MAC address is checked. And, in. Cut row fragment, free frame. Is forwarded. After. 64. Bytes of the frame. Is checked. Let's. Go ahead with the POA. Power, over ethernet now. Power. Internet. Describes. Any systems. Which pass electric. Power along, with data on twisted. Pair internet, cabling. This. Allows, a single cable to provide, both data connection. And electric. Power to devices, such as wireless. Access points. IP cameras. And VoIP, phones. To. Provide electric, over, data cables, to end devices, and care, devices also, must be supporting. P OE technologies. To, in, here we are seeing, a pure e switch, and we. Have an access, point IP, camera. Industry. Sensor, and work, phone, connected. To our Puri, switch, if. This, switch is supporting. Puri and also. This, waveform. Sensor. IP. Camera. And access, point are. Supporting. To Pew II feature -, we. Don't, need an extra. Power, cable. We don't need an extra, power adapter, we don't need anything, else we. Can provide, the power of these, devices, by. Using t, twisted. Pair copper.
Cables. Let's. Take a look to the fixed, and, modular. Service, these are the types of the, switch, guys. Fixed. Configurations, which are fixed, in their configuration. What that means is, that you, cannot, add features. Or options. To the switch beyond, those that, originally. Came with the switch, the. Particular. Module, you purchase, that reminds, the features, and options available, for. Example if you purchase a, 24. Port Gigabit, Ethernet fixed. Switch you, cannot, add additional. Ports, when you need them there. Are typically. Different configuration. Choices, that vary in how many and what, types of ports, are included. And let's. Take a look to the modular, switch modular. Suites offer more. Flexibility. In their configuration. Modular. Switch typically. Come with different, sites, chasis. That allow, for the installation, of different. Number. Of modular. Line cards, the line cars actually contain. The ports, the. LAN card fits, into, the switch chess is like expansion. Cards fit into a PC. The, larger, the chasis, the, more modules, it can support. And mostly, this modular. Switch, can. Carry, high, traffic. And. Let's. Take a look a great, feature which, is tag, technology. A stackable. Which is a network switch that, is fully, functional. Operating. Standalone. But which, can also be set up to operate, together with, one or more other. Networks. Which with. This group of switch, showing. The characteristic. Of a single switch but. Having. The port capacity of. Some, combined. Sewage. The. Term stack. Refers. To group, of switch, that, have been set. Up in this way the. Common, characteristic. Of a sec, acting, as a single, switch, is that, there, is a single, IP address, for remote administration, of the stack as a whole not, an IP address for the, administration. For each, unique. Stack, and, the, lastly, we're gonna talk about SFB. Small, form-factor. Pluggable. The. Small form-factor pluggable is. A compact. Hot. Pluggable. Optical. Module, transceiver. Used. For both. Telecommunication. And. Telecommunications. Applications an. SLP. Interface. This guy, on, networking. Hardware, provides. The device with a modular. Interface. That the user can, easily, adapt. To where is fibre optic and copper. Networking, standards, this, is a fiber. Optic SFP, and there, are also types. Of this SFP, which which. Supports, the copper. Cables, as well.
2020-06-10 09:13
