Section 4: TCP/IP Model Flashcards
What is the TCP/IP Model?
An alternative 4-layer model to the OSI model.
What is the network interface (Layer 1)?
At the Data Link & Physical Layer
Describes how to transmit bits across a network and determines how the network medium is going to be used
Examples: Ethernet, Token Ring, FDDI, RS-232
What is the Internet (Layer 2)?
At the Network Layer
Packages data into IP datagrams
Examples: IP, ICMP, ARP, RARP
What is the transport layer (Layer 3)?
At the Transport Layer
*Check this on video
Examples: TCP, UDP, RTP
What is the application layer (Layer 4)?
*Check this on video
Examples: HTTP, TELNET, FTP, SNMP, DNS, SMTP, SSL, TLS
How many port numbers can there be?
65,535
From what port number to port number are “well-known” and reserved?
0 - 1023
What are ephermeral ports? and from what port number to port number can be selected?
Short-lived transport port that’s automatically selected from a predefined range. 1024-65,535
What does an IPv4 Packet consist of?
Consists of a source address, destination address, IP flags, and protocol
How many bytes does a TCP header have?
20 Bytes
How many bytes does a UDP header have?
8 Bytes
What is File Transfer Protocol (FTP) and what port numbers does it use?
Transfers computer files between a client and server on a computer. Ports 20 & 21
Unsecure method
What is Secure Shell (SSH) and what port number does it use?
Cryptographic network protocol for operating network services securely over an unsecured network. Port 22
Best known for remote login to computer systems by users
What is the Secure File Transfer Protocol (SFTP) and what port number does it use?
Provides file access, file transfer, and file management over any reliable data stream. Port 22
What is Telnet and what port number does it use?
Provides bidirectional interactive text-oriented communication facility using a virtual terminal connection. Port 23
Like SSH, but insecure
What is Simple Mail Transfer Protocol (SMTP) and what port number does it use?
Internet standard for sending electronic mail. Port 25
What is Domain Name Service (DNS) and what port number does it use?
Hierarchical decentralized naming system for computers, services, or other resources connected to the Internet or a private network. Port 53
Converts domain names to IP addresses