Intro To Protocols Flashcards
File transfer protocol
Transfer of computer files between a client and server
What ports does FTP use ?
20 for data transfers
21 for control (commands and responses)
What does FTP allow users to do ?
Upload, download, delete, and manage files on a remote server without encrypting its traffic
Secure file transfer protocol
Extension of SSH to provide a secure method for transferring files
What port does SFTP use ?
Port 22
Telnet
Text-oriented communication facility using a virtual terminal connection
Which port does telnet use ?
Port 23
What is telnet known for ?
Being insecure since it transmits data in plaintext
Secure shell
Provide a secure channel over an unsecured network
When is SSH recommended ?
When connecting to servers,switches, and routers
What does SSH support?
Secure logging in, file transfers, and port forwarding
What does SSH encrypt ?
All traffic including passwords
What does SSH replace ?
FTP and telnet
What are two traits of DNS ?
Hierarchical and decentralized naming system
What port does DNS use ?
Port 53
What port does SSH use ?
Port 22
Through what protocols can DNS be sent ?
Via TCP or UDP protocols
What does DNS do ?
Translates more readily memorized domain names to the numerical IP addresses
Dynamic host configuration protocol
Automatically assigns an IP address
Which ports does DHCP use ?
UDP 67 (server)
UDP 68 (client)
What can DHCP provide IP addresses?
Automatic and centralized management of IP addressing
What does DHCP allow devices to do ?
Obtain IP addresses, subnet masks, default gateways, and DNS server information without manual configuration
Trivial file transfer protocol
FTP with no authentication
What port does TFTP use ?
Port 69
What is TFTP typically used for ?
Transferring boot files or configurations to devices in a local network
Where is TFTP generally used ?
In controlled environments
Hypertext Transfer protocol
Provides a standard for web browsers and servers to communicate
Which port does HTTP use ?
Port 80
What does HTTP transfer ?
Hypermedia documents (HTML)
What is HTTP considered ?
A stateless protocol where each command is executed independently
HTTPS/TLS
HTTPS when using TLS enhances security further compared to SSL
What is the port for HTTPS ?
443
What does the 443 port provide when web browsing ?
Secure web browsing by encrypting the data and ensuring the integrity and security of the data transmitted
Transport Layer Security
Standard security technology for establishing an encrypted link between web serves and browsers
Simple Mail Transfer Protocol
Email transmission across the internet
What is SMTP primarily for, and what port does it use ?
Uses port 25 to primarily send emails from an email client to an email server or between servers
SMTP over TLS (SMTPS)
SMTP secure email transmission over TLS
What port and protocol does SMTPS use ?
TCP port 587
Where does post office protocol v3 retrieve emails from ?
Retrieves email from a remote server
What situations is POP3 designed for ?
Client access the mail server infrequently or needs to operate online
POP3 over SSL
Encrypted alternative used for securely retrieving email from a remote server
Why is IMAP preferred over POP3 ?
Provides synchronization across all devices by multiple clients
IMAP over SSL
Protects the transmission of email data and credentials against interception
Network Time Protocol
Synchronized the clocks of computers over a network
What port does POP3 use ?
Port 110
Which port is used for the secure version of POP3 (POP3 over SSL) ?
Port 995
Which protocol and port does NTP use ?
UDP port 123
What is NTP designed to do ?
Mitigate variable network latency
Simple Network Management Protocol
Manages devices on IP networks
On which ports does SNMP operate ?
UDP 161 for sending commands from a management station to the network devices
UDP 162 for receiving
What does SNMP help network admins with ?
Manage network performance, find and solve problems, and plan for growth
Which version of SNMP is secure and encrypted ?
Only v3
Lightweight Directory Access Protocol
Access and maintain distributed directory information services
What port does LDAP use ?
TCP/UDP port 389
What does LDAP provide when working with directories ?
Mechanism for connecting to, searching, and modifying internet directories
LDAP over SSL (LDAPS)
Securing directory services, queries, and mods
Which protocol and port does LDAPS use ?
TCP port 636
Server Message Block
Network file sharing and requesting services from server programs
Which port and protocol does SMB use ?
TCP port 445
Is SMB used on a local network? What is it referred as?
Yes, inter-process communication
Syslog
Message logging to track and record system messages
What aspects makes Syslog crucial for networks?
System monitoring, troubleshooting, and security auditing
Which transport protocols can be used for Syslog ? What port is typically used ?
UDP (typically port 514), TCP, TLS/SSL
SQL server
Relational database management system developed by Microsoft
Which port is essential for SQL ? What transport protocol does it use ?
TCP port 1433
Remote Desktop Protocol
Enables remote connections primarily running Windows OS
Which port and protocol does RDP use ?
TCP port 3389
How is RDP used ?
For encrypted remote admin, remote work, IT support, and secure access to remote desktops and applications
Session initiation protocol
Signaling protocol used for initiating, modifying, maintaining, and terminating real-time sessions of video, voice, messaging, and other communications
Which layer does SIP operate ?
Application layer
Which protocols and ports does SIP use ?
TCP and UDP either port 5060 or 5061 over TLS
Is SIP fundamental for VoIP ?
Yes, enabling the establishment of call sessions and multimedia distribution
Internet control message protocol
Send diagnostic or control messages between network devices to manage and troubleshoot networks
Why is ICMP utilized ?
Error reporting
Where does ICMP operate ?
On top of IP, providing feedback without carrying application data
TCP
Connection-oriented provides reliable, ordered, and error-checked delivery
How many bytes of overhead does TCP use ?
24-60 bytes
Five methods TCP ensures packet transmission ?
Acknowledgment, retransmission, windowing, flow control mechanisms, and sequence numbers
Connectionless-communication
Sending data between devices without establishing a dedicated connection
Connect-oriented
Requires a connection to be established before data is exchanged
How to choose between TCP and UDP
Depends on the applications requirements
TCP 3-way handshake
SYN,SYN-ACK, ACK
UDP
Doesn’t need to establish a prior connection providing speed but less reliability
How much overheard does UDP use ?
8 bytes
What are some UDP applications ?
Streaming audio and video or gaming
Generic routing encapsulation
Tunneling protocol that can encapsulate a wide variety of network layer protocol packets inside IP tunnels
What does GRE create ?
A virtual point-to-point link
Where is GRE commonly used ?
VPNs and carrying network Protocols across networks that do not natively support them
IPSec
Designed to secure IP communications by authenticating and encrypting each IP packet in a data stream
Where is IPSec used ?
In securing internet communications and establishing VPNs
Two modes of IPSec ?
Transport and tunnel mode
Transport mode
Encrypts the payload of each packet but leaves the header untouched
Tunnel mode IPSec. Where is it also used ?
Encrypts the payload and the header. Is used for VPNs
Authentication Header
Component of IPSec used for authentication, integrity, and nonrepudiation through digital signatures
What does Encapsulating Security Payload provide ?
Adds encryption to ensure confidentiality of the data being transmitted
