Networking Core Protocols Flashcards
At what OSI layer does DNS operate on?
(7) Application layer
What is DNS an abbreviation for?
Domain Name System
What transport protocols does DNS use?
TCP and UDP
What records does DNS have?
A (IPv4), AAAA (IPv6), CNAME (Canonical Name: Domain name to domain name) and MX (MailExchange)
What CLI tool can you use to look up the IP of a domain such as www.example.com
nslookup (on both Windows and Linux)
[CMD] whois www.JeppeOgFredrika.dk
anvender whois som cmd værktøj til at slå op informationer om domænet jeppeogfredrika.dk
How would you via telnet use HTTP to retrieve a file.html from ip 10.44.238.25 on the default http port?
telnet 10.44.238.25 80 (ip port)
GET /file.html HTTP/1.1
Host: anything
[Acronym] FTP
File Transfer Protocol
What port does FTP listen on by default?
21
FTP command to download a file once connected, and location on local machine once downloaded?
“get filename” and will be in the pwd/cd of where the ftp client command was executed
[CMD] Connect to an ip via ftp
ftp ip
[Acronym] SMTP
Simple Mail Transfer Protocol
Default port for Simple Mail Transfer Protocol (SMTP)?
25
Which SMTP command indicates that the client will start the contents of the email message?
DATA
[SMTP] What does the client send to indicate that the e-mail has been fully entered?
A dot on a new line (“.”)
Default port for Post Office Protocol 3? (POP3)
110
[Acronym] POP3
Post Office Protocol 3
What is POP3 used for?
retrieving e-mails
[Acronym] IMAP
Internet Message Access Protocol
What is the key features of IMAP in comparison to POP3?
You can access the e-mails from various clients (e.g your laptop & your smartphone) whereas POP3 downloads and deletes the e-mail retrived from a server (resulting in that only one client would be able to consume it)
Is asynchronization a key aspect of Internet Message Access Protocol (IMAP)?
No. Synchronization is. Actions like marking emails as read, deleting emails, or organizing them into folders are synchronized across all devices.
What is IMAP designed for?
IMAP is designed for accessing and managing emails from multiple devices while keeping them synchronized.
What is POP3 designed for?
POP3 is designed for simple retrieval and storage of emails on a single device, with limited support for multi-device access
Default port for Internet Message Access Protocol (IMAP)?
143
Default port for Domain Name System (DNS)?
53
