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
What is DHCP reservation?
IP addresses are assigned by MAC address in the DHCP server to help manage addresses from one location
HTTP and HTTPS is for communication taking place where?
in the browser
In the clear HTTP and encrypted HTTPS is supported by which web servers and clients?
Nearly all
What is the port number for POP3?
tcp/110
What type of functionality does POP3 have?
basic mail transfer functionality
What’s the port number for IMAP4?
tcp/143
Which protocol includes email inbox management from multiple clients?
IMAP4
What does SMB stand for?
Server Message Block
What is SMB used for? What clients are supported?
protocol used by Windows for file sharing, printer sharing
What is SMB also called?
CIFS (Common Internet File System)
What port numbers does NetBIOS over TCP/IP use?
udp/137 (netBIOS name services nbname)
tcp/139 (netBIOS session service nbsession)
What does NetBIOS stand for
Network Basic Input/Output System
What is the port number for NetBIOS-less?
tcp/445
What is NetBIOS-less communication?
Direct SMB communication over TCP without NetBIOS transport
What does SNMP stand for?
Simple Network Management protocol
What does SNMP do?
Gathers statistics from network devices and manage them
What port does SNMP use for queries?
udp/161
What port does SNMP use for traps?
udp/162
How many versions of SNMP are there? Which is the most secure?
3 versions
3rd version is the most secure standard, others were in the clear communication
What does LDAP stand for?
Lightweight Directory Access Protocol
What port does LDAP use?
tcp/389
What does LDAP do?
Stores and retrieves information in a network directory (commonly used in Microsoft Active Directory)
What port does RDP use?
tcp/3389
What does RDP allow you to do?
Share a desktop from a remote location available on many Windows versions
With RDP can you connect to an entire desktop or just an application?
Yes
What clients are compatible with RDP? 6
Windows, macOS, Linux, Unix, iPhone, Android, etc
What does NetBIOS name service do?
Register, remove, and find Windows services by name
What does NetBIOS session service do?
Windows-connected oriented data transfer
What is an SNMP query?
gathers statistics from network devices and allows you to manage them
What is an SNMP trap?
allows you to receive alerts from network devices
What protocol allows you to perform encrypted console access?
SSH
