2.1 Common Network Ports Flashcards
For well-known port numbers, what 2 things need to match?
Client and server
What are the port numbers for FTP?
tcp/20 (active mode data)
tcp/21 (control)
What does FTP do?
Transfers files between systems with full-featured functionality such as List, add, delete, etc
How does FTP authenticate users?
With a username and password (some systems use a generic/anonymous login)
What is the port number for SSH?
tcp/22
SSH looks and acts just like what?
Telnet
What is Telnet’s port number?
tcp/23
What does Telnet allow us to do?
Allows us to log in to a device remotely using in-the-clear communication (not secure)
What is the port number for SMTP?
tcp/25
What is SMTP’s function?
Server-to-server email transfer, also used by mobile devices and email clients to send mail
What protocols are used to receive mail?
IMAP, POP3
What is DNS’s port number?
udp/53
What does DNS do?
Converts names to IP addresses
Usually, multiple DNS servers are in production. T or F?
True, they are very critical resources
What are the ports for DHCP?
udp/67
udp/68
What’s the purpose of DHCP?
Automatic configuration of IP address, subnet mask, etc
What does DHCP require?
A DHCP server
Where can you find DHCP servers? (3)
Its own server, as an appliance, integrated into a SOHO router, etc
How are dynamic IP addresses assigned by DHCP?
taken from a pool of IP addresses in real-time
How long do assigned IP addresses last?
Each system is given a lease and must renew the IP address at certain intervals