Day 31 Flashcards
Describe OSI vs TCP/IP Model
OSI - 7 Layers
TCI/IP - 4 (Network, Internet, Transport, Application)
OSI L7
Application
Refers to the interfaces between network and application software. Also includes authentication services .
Which layer includes authentication?
L7 - Application
OSI L6
Presentation
Defines the format and organization of data. Includes ENC
Which layer includes encryption?
L6 - Presentation
OSI L5
Session
Establishes and maintains end-to-end bidirectional flows between endpoints.
Includes Managing transaction flows
OSI L4
Transport
Host-to-Host Communications, including connection establishment and termination, flow control, error recovery, and segmentation of large data.
OSI L3
Network
Logical Addressing, routing, and path determination
OSI L2
Data Link
Formats data into frames appropriate for transmission onto some physical medium.
OSI L1
Physical
Defines the electrical, optical, cabling required for transmitting bits.
TCP/IP Layer 4
Application
TCP/IP Layer 3
Transport
TCP/IP Layer 2
Internet
TCP/IP Layer 1
Network Access
TCP/IP Application Layer Protocols
DNS, Telnet, SMTP, POP3, IMAP, DHCP, HTTP, FTP, SNMP
TCP/IP Transport Layer Protocols
TCP/UDP
TCP/IP Internet Layer Protocols
IP, ARP, ICMP
DNS
Domain Name System
Provides the IP address of a website or domain name.
Port 53
Telnet
Enables admin to log in to a host from a remote location.
Port 23
SMTP
Simple Mail Transfer Protocol
Sending of email.
Port 25
POP3
Post Office Protocol
Sending of email.
Port 110
IMAP
Internet Message Access Protocol
Sending of email
DHCP
Dynamic Host Configuration Protocol
Assigns IP addressing to clients
Port 67, 68
HTTP
Transfers data between web clients
Port 80
FTP
File Transfer Protocol
Facilitates the download and upload of files between FTP client and FTP Server
Port 20, 21
SNMP
Simple Network Messaging Protocol
Enables Network management systems to monitor devices attached to the network.
Port 161
TCP
Supports virtual connections between hosts on the network.
UDP
Connectionless
ARP
Address Resolution Protocol
Finds a host’s hardware address when only the IP address is known.
ICMP
Internet Control Message Protocol
Sends error and control messages.
OSI L7 PDU
Data
OSI L6 PDU
Data
OSI L5 PDU
Data
OSI L4 PDU
Segment
OSI L3 PDU
Packet
OSI L2 PDU
Frame
OSI L1 PDU
Bits