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
Acronym
TLS
- Transport Layer Security
- Replacement for SSL
- Encrypts FTPS
Should be used in place of SSL for browsers using HTTPS
Acronym
IPsec
- Internet Protocol Security
- Used to encrypt IP traffic
Acronym
SSH
- Secure Shell
- Encrypts SCP and SFTP
- Uses TCP port 22
Acronym
SFTP
- Secure File Transfer Protocol
- Uses SSH to transmit files in an encrypted format.
Transmits data using TCP port 22
Acronym
FTPS
- File Transfer Protocol Secure
- Uses TLS to encrypt FTP traffic
Acronym and definition
SMTP
- Simple Mail Transfer Protocol
- Transfers email between clients and SMTP servers
- TCP port 25 for unencrypted email
- SMTPS uses TCP port 587 for encrypted
Acronym
POP3
- Post Office Protocol
- Transfers emails from servers to end users
- TCP Port 110 for unencrypted connections
- TCP Port 995 for encrypted connections
Acronym
IMAP
- Internet Message Access Protocol
- Used to store email on a mail server and allows users to organize and manage email in folders on the server
- TCP Port 143 for unencrypted connections
- TCP Port 993 for encrypted connection
Acronym
HTTP
- Hypertext Transfer Protocol
- Transmits unencrypted web traffic between web servers and browsers
- TCP Port 80
Acronym
HTTPS
- Hypertext Transfer Protocol Secure
- Adds TLS encryption
- Port 443
Acronym and Definition
SPF
- Sender Policy Framework
- Uses DNS records to define which IP addresses are authorized to send emails on behalf of a domain
Acronym and Definition
DKIM
- DomainKeys Identified Mail
- Uses Public key cryptography to sign and verify an email’s domain and content
Acronym
DMARC
Domain-based Message Authentication, Reporting, and Conformance
What protocols protect users from spam, phising and other types of email based attacks?
SPF, DKIM, and DMARC
What are email gateways
Network devices or software applications that filter incoming and outgoing emails for spam malware and other types of threats
What port does LDAP use?
Port 389