Exam 2 (Material from Chapters 5 - 9ish) Flashcards
(173 cards)
What are the layers of the OSI model?
Layer 7: Application
Layer 6: Presentation
Layer 5: Session
Layer 4: Transport
Layer 3: Network
Layer 2: Data Link
Layer 1: Physical
Explain the function of each layer of the OSI model?
Layer 7: Application - User interface
Layer 6: Presentation - Data format; encryption
Layer 5: Session - process-to-process communication
Layer 4: Transport - end-to-end communication
Layer 3: Network - routing data; logical addressing; WAN delivery
Layer 2: Data Link - Physical addressing; LAN delivery
Layer 1: Physical - Signaling
What is the difference between a WAN and a LAN?
Wide area networks (WANs)
- Connect systems over a large geographic area
Local area networks (LANs)
- Provide network connectivity for computers located in the same geographic area
What are some WAN Connectivity Options?
Cable modem
Digital subscriber line (DSL)
Fiber optics
Satellite
Dialup
Cellular 3G/4G/5G networks
What is the Ethernet standard?
- Defines how computers use Media Access Control (MAC) addresses to communicate with each other on the network
- Governs both the Physical and Data Link layers of the OSI Reference Model
What is a hub?
- Contain a number of plugs, or ports, where you can connect Ethernet cables for different network systems
- Echo incoming packets to all ports
What is a switch?
- Perform intelligent filtering
- Know the MAC address of the system connected to each port
- When a switch receives a packet on the network, they look at the destination MAC address and send the packet only to the port where the destination system resides
What is a virtual LAN?
- A collection of logically related network devices that are viewed as a partitioned network segment
- Give administrators the ability to separate network segments without having to physically separate the network cabling
- Can be used to isolate logical groups of devices to reduce network traffic and increase security
Transmission Control Protocol/Internet Protocol (TCP/IP) and How It Works
- A suite of protocols that operate at both the Network and Transport layers of the OSI Reference Model
- Governs all activity across the Internet and through most corporate and home networks
- Developed by the Department of Defense to provide a highly reliable and fault-tolerant network infrastructure (security was not a focus)
Internet Protocol version 4 (IPv4) addresses
are how many bytes long?
Four bytes or 32bits
Internet Protocol version 6 (IPv6) addresses
are how many bits long?
128 bits
Are IPv4 or IPv6 addresses more secure?
IPv6
What is DHCP?
Dynamic Host Configuration Protocol (DHCP)
- Allows each computer to get its configuration information dynamically from the network instead of manually
- Provides a computer with an IPv4 address, subnet mask, and other essential communication information
What is port 20?
File Transfer Protocol (FTP) data transfer
What is port 21?
File Transfer Protocol (FTP) control
What is port 22?
Secure Shell (SSH)
What is port 25?
Simple Mail Transfer Protocol(SMTP)
What is port 53?
Domain Name System(DNS)
What is port 80?
Hypertext Transport Protocol (HTTP)
What is port 110?
Post Office Protocol v3 (POP3)
What is port 139?
Network Basic Input/Output System (NetBIOS) Session Service
What is port 143?
Internet Message Access Protocol (IMAP)
What is port 443?
HTTP over Secure Sockets Layer (SSL)
What is port 989?
File Transfer Protocol over SSL/Transport Layer security (FTPS) for data