Chapter 3 Flashcards
Acronym and Definition
OSI model
- Open Systems Interconnection model
- Describes network communications using seven layers
What are the layers of the OSI model in order?
- Physical
- Data Link
- Network
- Transport
- Session
- Presentation
- Application
The lower the layer number, the closer you are to the actual wires and cabling of the network
“Please Do Not Throw Sausage Pizza Away “
Physical layer of the OSI model
basic equipment of networking: copper wires, fibre optic cables, radio waves
Data Link layer of OSI
- This is where network switches reside.
- Formats data into data frames and routes it between systems on the local network using their MAC addresses
Network layer of the OSI model
Routers use IP addresses to send information between systems that are not on the same local network
Transport layer of the OSI model
Provides end-to-end communication services for applications. TCP and UDP exist at this layer
Session layer of the OSI model
establishes, manages, and terminates sessions between applications running on different devices, alowing them to commmunicate and exchange data
Presentation layer of the OSI model
- Translates data into a standard format that can be understood by the application layer.
- Provides encryption, compression, and other data transformation services
Application layer of the OSI model
Provides network services to application, allowing them to communicate with other applications over the network
Acronym
MAC
Media Access Control
Acronym
IP
Internet Protocol
Acronym and definition
TCP
- Transmission Control Protocol
- A connection oriented protocol that provides guaranteed delivery
Uses three-way handshake process
Acronym and definition
UDP
- User Datagram Protocol
- A connectionless protocol that provides “best effort” delivery, to deliver data without using extra traffic
Many DoS attacks use UDP
Walkthrough the three way TCP handshake process
- To start the TCP session, the client sends a SYN (synchronize) packet
- The server responds with a SYN/ACK (synchronize/acknowledge) packet.
- The client completes the handshake with an ACK packet to establish the connection
Acronym
DoS
Denial of Service
A type of network based attack
Acronym and Definition
ICMP
- Internet Control Message Protocol
- Tests basic connectivity and includes ping and tracert
Acronym and Definition
IP
- Internet Protocol
- Identifies hosts in a TCP/IP network and delivers traffic from one host to another using IP addresses
- IPv4 uses 32 bit addresses
- IPv6 uses 128 bit addresses using hexadecimal code
Acronym and Definition
ARP
- Address Resolution Protocol
- Resolves IPv4 addresses to MAC addresses
What are use cases that may be associated with different protocols
- Data in transit
- Email and web
- Directory
- Voice and Video
- Remote Access
- Time Synchronization
- Network Address Allocation
- Domain Name Resolution
Acronym and Definition
FTP
- File Transfer Protocol
- Used to transfer files over networks in cleartext. Does NOT encrypt the transmission
This is an insecure protocol that should no longer be used to transfer data over a network
Acronym
TFTP
Trivial File Transfer Protocol
Not an essential protocol so is usually disabled by administrators. Used to transfer small amounts of data.
Acronym
SSL
- Secure Sockets Layer
- Used to be the primary method to secure and encrypt HTTP traffic as HTTPS and other types of traffic
- Has been compromised and is not recommended for use
Which protocols should not be used on modern networks
- FTP
- TFTP
- SSL
What are the secure alternatives for protecting data in transit?
- TLS
- IPsec
- SSH
- HTTPS
- FTPS