CNNA CHAPTER 1 (PASAR) Flashcards
A _______ can replace the hub, breaking up collision domains.
Switch
True or False
Hubs don’t segment a network, they just connect network segments together
True
_____ are used to connect network together and route packets of data from one network to another.
Routers
_____ break up a broadcast domain by default.
Routers
It is the set of all devices on a network that hear all the broadcast sent on that segment.
Broadcast domain
____ can also use packet filtering by using access lists. They also use routing table to make path selections and to forward packets to networks.
Routers
It is the map of internetwork
Routing table
It make a LAN network better by optimizing its performance and providing more bandwidth for the LAN’s users.
Switch
_____ break up collision domains
Switch
Switches break up ____ domains and routers break up ____ domains.
collision, broadcast
Switches and ____ basically do the same thing
bridges
Layer where the users actually communicate with the computer
Application layer
Presents data to the application layer and is responsible for data translation and code formatting
Presentation layer
Responsible for setting up, managing, and then tearing down sessions between presentation layer entities.
Session layer
Provides end-to-end data transport services and can establish a logical connection between the sending host and destination host of an internetwork.
Transport layer
Two protocols that work under transport layer
TCP and UDP
Layer at which data integrity is ensured by maintaining flow control
Transport layer
Prevents a sending host from one side of the connection from overflowing the buffers in the receiving host.
Flow control
When a machine receives a flood of datagrams too quickly for it to process it stores them in a memory section called a _____.
buffer
The quantity of data segments that the transmitting machine is allowed to send without receiving an acknowledgement for the is called a ______.
Window
They are used to control the amount of outstanding, unacknowledged data segements
Windows
Used to transport user data through the internetwork
Data packets
Used to update neighboring routers about the networks connected to all routers within the internetwork.
Route update packets
Protocol-specifi ……???
Network Addresses
Manage device addressing, tracks the location of devices on the network, and determines the best way to move data.
Network layer
Provides the physical transmission of the data and handles error notification, network topology, and flow control
Data Link layer
Ensures that the messages are delivered to the proper device on a LAN using hardware addresses
Data Link layer
The data link layer formats the message into pieces, each called a _________.
data frame
The two IEEE Data Link layer sublayers
MAC 802.3 and LLC 802.2
Defines how packets are placed on the media.
Media Access Control (MAC) 802.3
Responsible for identifying Network layer protocols and then encapsulating them.
Logical Link Control (LLC) 802.2
It sends bits and receives bits.
Physical Layer
It is a multiple-port repeater
hub
It receives a digital signal and reamplifies or regenerates that signal and then forwards the signal out all active ports …..
Repeater
Is a contention media access method that allows all the hosts on a network to share the same bandwidth of a link.
Ethernet
- is defined in the original 802.3 ethernet.
- uses only one wire pair with a digital signal running in both directions on the wire,
Half-duplex Ethernet
- uses two pairs of wires
- uses point-to-point connection
- no collision will occur
Full-duplex Ethernet
Used to connect:
1. Host to switch or Hub
2. Router to switch or Hub
Straight-through cable
Used to connect:
1. Switch to switch
2. hub to hub
3. host to host
4. router direct to host
Crossover Cable
Used to connect a host to router console serial communication (COM) port
Rolled Cable
Data Encapsulation Method
Data –> Segments –> Packets/Datagrams
–> Frames –> bits
The CISCO Three Hierarchical Model
Core layer
Distribution layer
Access layer
- Responsible for sending large amount of traffic both reliably and quickly.
- Used to switch traffic as fast as possible
Core layer
-Sometimes referred to as workgroup layer
- provides routing, filtering, and WAN access
Distribution layer
- Controls user and workgroup access to internetwork resources
- sometimes referred to as desktop layer
Access layer
is an ethernet term used to describe a network collection of devices in which one particular sends a packet on a network, forcing every other device on that same segment to pay attention to it.
Collision domain
Creates one collision domain and one broadcast domain.
Hubs
Breaks up collision domain but creates one large broadcast domain
Bridges
Break up broadcast domains (and collision domains) and use logical addressing to filter the network
Routers
1st connection agreement
Request for synchronization
2nd and 3rd connection agreement
Establishes connection
Final connection agreement
acknowledgement, notifies the destination host
It can occur because a high speed computer is generating data traffic a lot
Congestion
- virtual circuit is a setup
- uses sequencing
- uses acknowledgement
- uses flow control
Connection oriented service
If a host fails to receive all the segments that it should acknowledge, the host can improve communication by ______?
Decreasing the window size
A technique that requires a receiving machine to communicate w/o transmitting source by sending an acknowledgement pack to the sender when it receives data
Positive acknowledgement w/ retransmission
Protocols used to support data traffic
Routed protocols
Used to update neighboring packets
Route update packets
The exit interface packet will take when destined for a specific network
Interface
The distance to the remote network
Metric
The number of routers a packet pass through enroute to a remote network
Hop count
DLL will ensure that all messages are delivered to the proper device on a LAN using ______?
Hardware addresses
Data Link Layer sublayer that identifies network layer protocols and encapsulates them
LLC 802.2
Used for physical addressing
MAC 802.3 and 802.5
Time measured from when a frame enters a port to the time it exits a port
Latency
If the destination is on a different segment, the frame can be transmitted only to the segment called ?
Transparent bridging
Take note
nibble - 4 bytes
byte -8 bits
Converted by reading nibbles not bytes
Hexadecimal addressing
Has 1 nibble, 2 hex characters
Hex character
DCE stands for (old and new)
New:
Data Communication Equipment
Old:
Data Circuit-Terminating Equipment
Can be found at the service provider
DCE
Can be found at the attached device
Data Terminal Equipment (DTE)
The services available to the DTE are most often accessed via a modem ______
Channel Service Unit/Data Service Unit (CSU/DSU)
Is a multipoint repeater
Hub
Protocol that helps devices share the same bandwidth
CSMA/CD
Determines when the colliding stations can retransmit
Backoff algorithm
Effects of CSMA/CD
Delay
Congestion Avoidance
Low throughput
When a full duplex ethernet port is on, it first connects to the remote called____.
Auto-detect mechanism
Mechanism that decides on the exchange capability
Auto-detect mechanism
Burned into each NIC
MAC
Note:
MAC - 48 bits (6bytes)
MAC hex code
FF:FF:FF:FF:FF:FF
OUI has how many bits
24 bits or 3 bytes
Used in DLL to encapsulate packets handed down from the network layer
Frames
The function of the __________ is to pass data frames between each other using _________.
Ethernet station ; MAC frame format
Encapsulating a frame within different type of frame
Tunneling
One octet synch
Start Frame Delimiter (SFD)
In 10101011, the last “1” allows the receiver to _______
alternate 1’0
It transmits a 48 bit value using LSB
Destination Address
LSB
Least Significant Bit
Identifies the transmitting device
Source Address
802.3 uses a ________ field while Ethernet uses a _______ field.
length ; type
Packet sent to DLL from layer 3
Data
Size of packet sent to DLL from layer 3
64-1500 bytes
Used to store CRC
FCS
Note
802.3 —— Ethernet
802.3u —– Fast Ethernet
802.3ab —- Gigabit Ethernet
802.3ae —- 10Gbps over fiber and coaz
Each of the 802.3 standard defines an _____ which allows one bit at a time transfer to the physical link from DLL
Attachment Unit Interface (AUI)
Provides 100Mbps throughput that uses a nibble
Media Independent Interface (MII)
Ethernet uses a
Gigabit Media Independent Interface (GMII)
Breaking up a really big network into a number of smaller ones
Network Segmentation
Routers by default break up a
Broadcast domain
Routers can also provide packet filtering using
Access list
Routers use a _______ to make path selection.
Routing table
Used to reduce collision domains within broadcast domain and increase the number of collision domains
Bridging or Bridges
CISCO calls the Multiport Bridges and was introduced before routers and hubs
Bridging or Bridges
NOTE
Using hubs can contribute to congestion on your Ethernet
Router functions
Packet switching
Packet filtering
Internetwork Communication
Path Selection
IBM
International Business Machines Corporation
NOTE
If broadcast domains are too large:
- users have less bandwidth
- requires to process more broadcast
- Network response is slow
Conceptual blueprint of how communication should take place
Reference model
Logical groupings
Layer
Network devices that operates @ the OSI Model
- Network Management System (NMS)
- Web and Application servers
- Gateways (not default)
- Network host
Emily Post of the network protocol world
ISO
NOTE/MEMORIZE
Layer Functions:
1. APPLICATION
- file, print , message, data base, application services
- PRESENTATION:
- data encryption, compression, translation - SESSION:
- Dialog control - TRANSPORT:
- End-to-End encryption - NETWORK:
- Routing. - DATA LINK
- Framing - PHYSICAL
- Physical topology
Used to view a local HTML
NIC
- used at the transport layer
- means acknowledgement, sequencing, and flow control
Reliable
Data integrity is ensured at the transport layer by maintaining ______>
Flow control
Transmitting device first establishes a connection -oriented session w/ its peer system
Call setup/three way handshake
When the transfer is finished, a _______ takes place to tear down the virtual circuit
Call termination
Is a virtual setup
Overhead
Types of flow control
Buffering
Windowing
Congestion Avoidance
EIA/TIA category 5, 6, or 7 UTP two-pair wiring. One user per segment; up to 100 meters long. It uses an RJ45 connector with a physical star topology and a logical bus.
100BaseTX (IEEE 802.3u)
Uses fiber cabling 62.5/125-micron multimode fiber. Point-to-point topology; up to 412 meters long. It uses an ST or SC connector, which are media-interface connectors.
100BaseFX (IEEE 802.3u)
Copper twisted-pair called twinax (a balanced coaxial pair) that can only run up to 25 meters.
1000BaseCX (IEEE 802.3z)
Category 5, four-pair UTP wiring up to 100 meters long.
1000BaseT (IEEE 802.3ab)
MMF using 62.5- and 50-micron core; uses an 850 nanometer laser and can go up to 220 meters with 62.5-micron, 550 meters with 50-micron.
1000BaseSX (IEEE 802.3z)
Single-mode fiber that uses a 9-micron core and 1300 nanometer laser and can go from 3 kilometers up to 10 kilometers.
1000BaseLX (IEEE 802.3z)
a balanced coaxial pair
Twinax
If you want a network that is susceptible to EMI, use a __________ to provide a more secure, long distance cable.
fiber-optic cable
Once you have the correct cable connected from your PC to the CISCO router or switch, you can start __________ to create a console connection and configure the device.
Hyperterminal
In order for host A to ping host B, a ______ is needed to connect the two switches.
crossover cable
When a host transmits data across a network to another device, the data goes through ________.
encapsulation
To communicate & exchange information, each layer uses .
PDUs
The ______ is responsible for finding the destination hardware address that dictates where the packets should be sent on the local network. It does this by using ________.
network layer ; ARP
The network layer adds a header, and adds the logical address to the front of each segment. Once the header is added to the segment, the PDU is called a _____.
packet
9600 ——– BPS
Helps us understand where things belong, how things fit together and what functions go where
Hierarchy
IS an issue at the core layer of CISCO Hierarchical model
Fault tolerance
Communication point between the core and access layer of the CISCO Hierarchical Model
Distribution layer
breaks up collision domains but create one large broadcast domain by default
Switches
