Network Fundamentals Flashcards
OSI Model
Physical, Data, Network, Transport, Session, Presentation, Applications
Physical Layer
defines how data is sent through network (hubs)
Data Layer
tranfer data between two nodes (switches, MAC, NIC)
Network layer
allows hosts to send packets between networks (ping, tracert) Routers work here
Transport
handles data transfer between end systems, how much data sends, rates, destinations (Flow control, reliability)
Session
creates and maintains session (IP, logical addresses, routers)
Presentation
prepeare/translate data from app format to network format (encryption/decryption)
Applications
offers services directly to apps (SSH, FTP)
DNS, DHCP, SSH, HTTP, HTTPS, SNMP, SMTP all examples of what?
Application Layer
Encryption, Encoding, SSL, JPEG, MPEG, MIDI all examples of what?
Presentation
NFS, RPC, SQL all examples of what?
Session
TCP, UDP, RTP all examples of what?
Transport
IPv4, IPv6, ICMPv4, ICMPv6, IPX all examples of what?
Network
Ethernet, PPP, FDDI, ATM, IEEE 802.5/802.2, HDLC all examples of what?
Data Link
Ethernet (IEEE802.3), Wi-fi (IEEE 802.11), FDDI, V.35, V.24 all examples of what?
Physical
Data encapsulation
Process of adding headers and trailers using OSI model, starts with application layer
Data Decapsulation
extracting info from a reverse OSI model process, starts with Physical Layer
Stateful Firewall
More security features, more resource heavy, complex, keeps connection to analyze network traffic
Stateless Firewall
Examines individual packets without maintaining a connection
TCP vs. UDP
TCP ideal for apps where data integrity is crucial. UDP low-latency comms, suitable for real-time apps
ARP
Address Resolution Protocol - operates in Layers 2 + 3 (Every Layer 3 device uses ARP)
3-way handshake
responsible for comms between devices that use TCP
“SYN”, “SYN-ACK”, “ACK”
TCP/IP Model
Network Access, Internet, Transport, Application
In which layer of OSI and TCP/IP models are source and destination logical
addresses added to the packet?
OSI - Network Layer (3), TCP/IP - Internet Layer (3)
In which layer of OSI and TCP/IP are source and destination physical addresses added to the frame?
OSI - Data Link Layer (2), TCP/IP - Network Access (1)
What does UDP do with corrupted or out-of-order packets?
Nothing, the destination discards corrupted packets
