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1CSMA/CDCarrier Sense Multiple Access with Collision
Detection
2(CSMA/CD), which helps devices share the bandwidth evenly while preventing two devices from _________ ________ on the same network mediumtransmitting simultaneously
3Only ________ and _______ can affectively prevent a transmission from propagating throughout the entire networkswitches and routers
4When a host wants to transmit over the network, it first checks for the presence of a digital signal on the wire. If all is clear and no other host is transmitting, the host will then proceed with its transmission. But it doesn't stop there. The transmitting host constantly monitors the wire to make sure no other hosts begin transmitting. If the host detects another signal on the wire, it sends out an extended jam signal that causes all nodes on the segment to stop sending data—think busy signal. The nodes respond to that jam signal by waiting a bit before attempting to transmit again. Back-off algorithms determine when the colliding stations can re-transmit. If collisions keep occurring after 15 tries, the nodes attempting to transmit will then time out.When a host wants to transmit over the network, it first checks for the presence of a digital signal on the wire. If all is clear and no other host is transmitting, the host will then proceed with its transmission. But it doesn't stop there. The transmitting host constantly monitors the wire to make sure no other hosts begin transmitting. If the host detects another signal on the wire, it
sends out an extended jam signal that causes all nodes on the segment to stop sending data—think busy signal.
The nodes respond to that jam signal by waiting a bit before attempting to transmit again. Back-off algorithms determine when the colliding stations can re-transmit. If collisions keep occurring after 15 tries, the nodes attempting to transmit will then time out.
5When a collision occurs on an Ethernet LAN, the following happens:1. A jam signal informs all devices that a collision occurred.
2. The collision invokes a random back-off algorithm.
3. Each device on the Ethernet segment stops transmitting for a short time until its back-off timer expires.
4. All hosts have equal priority to transmit after the timers have expired.
6If a hub is attached to a switch, it must operate in ______ ______ mode because the end stations must be able to detect collisionshalf-duplex
7Half-duplex uses _________ protocol to help prevent collisions and to permit retransmitting if one occursCSMA/CD
8Full-duplex Ethernet uses two pairs of wires at the same time instead of a single wire pair like half-duplex. It also uses a ______ -__-______ connection between the transmitter of the transmitting device and the receiver of the receiving devicepoint-to-point
9keep in mind that a switch port connecting to a hub as well as the hosts connecting to that hub must run at ______ ______half-duplex
10When a full-duplex Ethernet port is powered on, it first connects to the remote end and then negotiates with the other end of the Fast Ethernet link. This is called an auto-detect mechanism. This mechanism first decides on the exchange capability, which means it checks to see if it can run at 10, 100, or even 1000 Mbps. It then checks to see if it can run full-duplex, and if it can’t, it will run half-duplex.When a full-duplex Ethernet port is
powered on, it first connects to the remote end and then negotiates with the other end of the Fast Ethernet link. This is called an auto-detect mechanism. This mechanism first decides on the exchange capability, which means it checks to see if it can run at 10, 100, or even 1000 Mbps.
It then checks to see if it can run full-duplex, and if it can’t, it will run half-duplex.
11There are no ______ in full-duplex modecollisions
12A dedicated _____ ______ is required for each full-duplex nodeswitch port
13The host ______ ____ and the switch port must be capable of operating in full-duplex mode.network card
14The default behavior of 10Base-T and 100Base-T hosts is ____ Mbps half-duplex if the autodetect mechanism fails, is always good practice to set the speed and duplex of each port on a switch if you can.10
15The MAC, or hardware, address is a ___-bit (6-byte) address written in a hexadecimal format.48
16—Ethernet addressing using MAC addresses
174 or 8 bits together, with these being referred to as a ______ and a _____, respectivelynibble
byte
18—
19All you have to remember is that each hex character is one nibble and that two hex characters joined together make a byte. To figure out the binary value, put the hex characters into two nibbles and then join them together into a byte. 6 = 0110; A, which is 10 in hex = 1010; so the complete byte would be 01101010.All you have to remember is that each hex character is one nibble and that two hex characters joined together make a byte. To figure out the binary value, put the hex characters into two nibbles and then join them together into a byte. 6 = 0110; A, which is 10 in hex = 1010; so the complete byte would be 01101010.
20_______ are used at the Data Link layer to encapsulate ______ handed down from the Network layer for transmission on a type of media access.Frames
packets
21The function of Ethernet stations is to pass data frames between each other using a group of bits known as a MAC frame format. This provides error detection from a ______ ______ ______ . But this is error detection, not error correctioncyclic redundancy check (CRC)
22A packet can vary from 46 to _____ bytes.1,500
23______ ______ ______ is a field at the end of the frame that’s used to store the cyclic redundancy check (CRC) answer.Frame Check Sequence (FCS)
24802.3u is _____ EthernetFast
25802.3ab is ______ Ethernet on category 5Gigabit
26802.3ae is ______ over fiber and coax10 Gbps
27____ ______ Ethernet is (802.3ba100 Gbps
28EIA/TIA (Electronic Industries Alliance and Telecommunications Industry Association) is the standards body that creates the ________ layer specifications for EthernetPhysical
29_________ is the unwanted signal interference from adjacent pairs in the cableCrosstalk
30__________ is (IEEE 802.3) 10 Mbps using category 3 unshielded twisted pair (UTP) wiring for runs up to 100 meters10Base-T
31_________ is (IEEE 802.3u) , most commonly known as Fast Ethernet, uses EIA/TIA category 5, 5E, or 6 UTP two-pair wiring up to 100m's long100Base-TX
32__________ (IEEE 802.3u) Uses fiber cabling 62.5/125-micron multi-mode fiber. Point to-point topology; up to 412 meters long. It uses ST and SC connectors, which are media interface connectors.100Base-FX
33__________ is (IEEE 802.3z) Copper twisted-pair, called twinax, is a balanced coaxial pair that can run only up to 25 meters and uses a special 9-pin connector known as the High Speed Serial Data Connector (HSSDC). Used in Cisco’s new Data Center technologies1000Base-CX
34_________ is (IEEE 802.3ab) Category 5, four-pair UTP wiring up to 100 meters long and up to 1 Gbps.1000Base-T
35__________ is (IEEE 802.3z) 1 Gigabit Ethernet running over multimode fiber-optic cable, using short wavelength laser. Multimode fiber (MMF) using 62.5- and 50-micron core; uses an 850 nanometer (nm) laser and go up to 220 meters with 62.5-micron, 550 meters with 50-micron1000Base-SX
36_________ is (IEEE 802.3z) Single-mode fiber that uses a 9-micron core and 1300 nm laser and can go from 3 kilometers up to 10 kilometers.1000Base-LX
37_____________ (Cisco standard) is a Cisco specified standard for Gigabit Ethernet communication. It operates on ordinary single-mode fiber-optic links with spans up to 43.5 miles (70 km).1000Base-ZX
38_________ (802.3.an) is a standard proposed by the IEEE 802.3an committee to provide 10 Gbps connections over conventional UTP cables, (category 5e, 6, or 7 cables). It allows the conventional RJ45 used for Ethernet LANs and can support signal transmission at the full 100-meter distance10GBase-T
39A network medium that is not susceptible to electromagnetic interference (EMI), ______ -______ _____fiber-optic cable
40The _______ _______ cable is used to connect the following devices: Host to switch or hub Router to switch or hubstraight-through
41The _______ _______ can be used to connect the following devices: Switch to switch Hub to hub Host to host Hub to switch Router direct to host Router to routercrossover cable
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47When a host transmits data across a network to another device, the data goes through a process called encapsulation and is wrapped with protocol information at each layer of the OSI model.encapsulation
48—
490 through ______ are reserved for well-known port numbers1023
50The ____ ______ is responsible for transporting large amounts of traffic both reliably and quickly.Core Layer
51If there’s a failure in the core, every single user can be affected! This is why _____ tolerance at this layer is so important.Fault
52The __________ layer is sometimes referred to as the work-group layer and is the communication point between the access layer and the core. The primary functions of the ________ layer are to provide routing, filtering, and WAN access and to determine how packets can access the core, if neededdistribution
53The ___________ layer is where we want to implement policies for the network because we are allowed a lot of flexibility in defining network operation heredistribution
54There are several things that should generally be handled at the ___________ layer: Routing - Implementing tools (such as access lists), packet filtering, and queuing -Implementing security and network policies, including address translation and firewalls -Redistributing between routing protocols, including static routing. -Routing between VLANs and other workgroup support functions -Defining broadcast and multicast domainsdistribution
55The ________ layer controls user and work-group access to inter-network resources. The _______ layer is sometimes referred to as the desktop layeraccess