Powerpoints Networking Flashcards
Networking: Clients vs. Servers:
Clients request information; Servers provide information to other devices on the network.
Peer-to-Peer:
Computers for both server and client
End Devices vs. Intermediary Network Devices:
End Devices: Source or destination of a message.
Intermediary: Connects multiple individual networks to form an inter-network, connects individual end device; ensures data flows across the network; and provides connectivity
Topology:
Physical and logical
Intranet, Extranet, and Internet differences
Intranet - Company
Extranet - Suppliers, customers, collaborators
Internet - the world
Traditional Separate /Converging Network:
Traditional: Each network with its own set rules and regulations.
Converging: Delivers data, voice and video over the same network infratructure.
Four characteristics of architecture (reliable network):
Fault tolerance-redundant network, limits impact of a failure, multiple paths between source and destination
Scalability-expands quickly to support new users and applications without impacting performance
QOS (Quality of Service)-priorities importance of communications
Security
confidentiality=intended authorized recipients can access and receive data
integrity-info in the data hasnt been altered during transmission
availability-timely and reliable access to data
Network trends:
BYOB, Online Collaboration, Video Communication, Cloud Computing
Security Threats vs. Security Solutions:
Threats: Virus, worm, trojan horses, spyware and adware, zero day attacks (zero hour), hacker, denial of service, data intercept and theft
Solutions: Antivirus and spyware, dedicated firewall, access control lists (ACL’s), intrusion prevention systems (IPS), virtual private network (VPN)
Rules of Communication vs. Network Protocols and Standards (rules that govern communication)
Communication:
Rule Establishment - ID sender and receiver, common language and grammar, speed and timing of delivery, conformation or acknowledgement requirements.
Message Encoding: Process of converting information into another acceptable form. Message formatting and encapsulation, message size, message timing (access method, flow control, response timeout), message delivery options (unicast, multicast, broadcast),
Network Protocals and Standards:
How message is formatted and structured, networking devices share information about pathways with other networks, how and when errors and system messages are passed between devices, and setup and termination of data transfer sessions.
Protocol Interaction:
Application and network access work together.
Segmentation / Multiplexing:
Segmentation breaks communications into pieces.
Multiplexing interleaves the pieces.
Network Address / Data Link Addresses
Network: Source/destination IP address; delivers IP packet from original source to final destination, same network or remote network.
Data Link: Source/destination data link address; delivers from one NIC to another NIC on same network.
Physical / Layer:
Accepts complete frame from data link layer; encodes it as series of signals that are Tx onto the local media. Functions: physical component, encoding, signaling.
Data Transfer (bandwidth vs. throughput)
Bandwidth: capacity to a medium to carry data.
Throughput: measure of the transfer of bits across the media.
Types of UTP (unshielded)
Rollover
Crossover (similar components)
Straight through (dissimilar components)
Data Link Layer
?
Data Link Sublayers (LLC / MAC)
LLC communicates with the network layer
MAC defines the media access process
MAC WAN Topologies:
Physical: Point-to-point, hub and spoke, mesh
Logical: Point-to-point
Detail link frame (what layer? and define)
- 11
- 3 ????
Layer 2 - header, packet (data), trailer
Header: frame start/addressing/type/controls
Packet: Data
Trailer: Error detection/frame stop
- 11 - wireless frame
- 3 - wired
Ethernet Encapsulation:
Data link layer and physical layer
MAC Sublayer:
Lowest sublayer of the data link layer,responsible for data encapsulation and media access control.
Ethernet Frame:
Adds headers and trailers around Layer 3 PDU to encapsulate the message being sent. Frame size is 64 bytes.
MAC Address:
48 bit long, expressed as 12 Hexidecimal digits. IEE requirements must use vendor’s assigned OUI as first three bytes, same OUI signal unique value in last 3 byes.
CAM (Content Addressable Memory):
In the ethernet switch, remembers whose MAC addresses are in each port; monitors source address; frame is forwarded based on the CAM.
Switch Forwarding Method (cut through, store and forward):
Store and Forward receives and stores the whole frame before it forwards it.
Cut Through forwards the frame before it’s entirely received, the destination frame must be read before it’s forwarded.
Two Cut Through Switching Types:
Fast Forward: Lowest level of latency forwards the packet after reading destination address.
Fragment-Free Switching: Stores first 64 bytes of frame before forwarding. Most network errors and collisions occur during first 4 bytes.
Full Duplex / Half Duplex:
Full - Both ends of the connection can send and receive simultaneously.
Half - Only one connection can send at a time.
Common cause of performance issues on ethernet links:
One port operates at half duplex and another on full duplex.
Auto-MDX:
Detects type of duplex needed for connection and configures automatically; helps reduce configuration errors.
Layer 2 / Layer 3:
Layer 2 - Addresses are used to move frame within local network.
Layer 3 - Addresses are used to move the packets through remote networks.
Combination of MAC and IP facilitate the _____ communication.
end-to-end
Where do the physical address and logical address come from?
Physical: MAC used on the NIC for same network communications.
Logical: IP address to send packets remotely, different network.
ARP (address resolution protocol):
Allows the source to request MAC address of the destination (Layer 3). ARP uses ARP requests and ARP Reply to perform its functions. Entries are removed from ARP table when cache timer expires. ARP-A on Windows PC
IPV4 Addresses:
32 bit divided into four sections called octets. Each octet contains 8 bits separated by a dot. 8 bits = 1 byte.
Static / Dynamic:
Static - type in manually.
Dynamic - DHCP - automatically configs IP addresses.
Private Addresses:
10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
Loopback 127.0.0.0/8
Linklocal 169.254.0.0/16
IPV4 and IPV6 Coexistance
Dual Stack - IPV4 / IPV6 same network
Tunneling - IPV6 packets inside IPV4 packets.
Translation - IPV6 packet translated to an IPV4 packets, and vice versus
