1.1 Common Ports Flashcards
SSH uses port _________________.
TCP/22
DNS uses port _________________.
UDP/53
SMTP uses port _________________.
TCP/25
SFTP uses port _________________.
TCP/22
FTP uses port _________________.
TCP/20 active mode
TCP/21 control
Telnet uses port _________________.
TCP/23
DHCP uses port _________________.
UDP/67
UDP/68 - Requires a DHCP server
TFTP uses port _________________.
UDP/69
HTTP uses port _________________..
TCP/80
HTTPS uses port _________________.
TCP/443
SNMP uses port _________________.
UDP/161
RDP uses port _________________.
TCP/3389
NTP uses port _________________.
UDP/123
SIP uses port _________________.
TCP/5060-5061
SMB uses port _________________.
TCP/445
POP3 uses port _________________.
TCP/110
IMAP4 uses port _________________.
TCP/143
LDAP uses port _________________.
TCP/389
LDAPS uses port _________________.
TCP/636
H.323 uses port _________________.
TCP/1720
Describe SSH
Secure Shell
TCP 22
Looks and acts the same as Telnet, but encrypted
Allows you to log in and control devices via commands
Describe DNS
Domain Name System
UDP 53
Converts names to IP addresses
Describe SMTP
Simple Mail Transfer Protocol
TCP 25
Internet standard for sending mail
Also used to send mail from a device to a mail server
Describe SFTP
Secure Shell File Transfer Protocol
TCP 22
Uses the SSH File Transfer Protocol tunnel
Provides file system functionality
Resuming interrupted transfers, directory listings, remote file removal.
Describe FTP
Transfers files between systems
TCP 20, 21
Authenticates with a username and password
We don’t use it because it is not encrypted.
Describe Telnet
Telecommunication Network
TCP 23
Not encrypted, insecure
Remote access command prompt
Console access
In-the-clear communication, no encryption
Not the best choice for production systems
Describe DHCP
Dynamic Host Configuration Protocol
UDP 67, 68
Automated configuration of IP address, subnet mask, and other options.
Addresses are assigned by MAC address
Describe SNMP
Simple Network Management Protocol
UDP 161
Provides collection and organization of information about managed devices on IP networks. Can manage settings of devices.
Gather statistics from network devices
v1 - The original structured tables, in the clear
v2 - A good step ahead, Data type enhancements, bulk transfers, still in the clear.
v3 - The new standard, Message encryption, authentication, encryption
Describe TFTP
Trivial File Transfer Protocol
UDP 69
Very simple file transfer application, read files/write files, transmits files in both directions using applications.
No authentication - Not used on production systems
Describe RDP
Remote Desktop Protocol
Share a desktop from a remote location over network using a GUI.
TCP 3389
Remote Desktop Services on many Windows versions
Can connect to an entire desktop or just an application
Clients for Windows, macOS, Linux, iPhone, and others
Describe NTP
Network Time Protocol
UDP 123
Switches, routers, firewalls, servers, workstations all have their own clock.
Synchronizing the clocks becomes critical for log files, authentification information, outage details.
Automatic updates (No flashing 12:00 lights)
Flexible - you control how clocks are updated.
Very accurate - better than 1 millisecond
Describe SIP
Session Initiation Protocol
TCP 5060-5061
Voice over IP (VoIP) signaling, Video calls, Instant Messaging
Setup and manage VoIP sessions (call, ring, hang-up)
Extend voice communication (video conferencing, instant messaging, file transfer)
Describe SMB
Server Message Block
TCP 445
Protocol used by Microsoft Windows for file sharing, printer sharing.
Also called CIFS (Common Internet File System)
Describe POP3
Post Office Protocol version 3
TCP 110
Basic mail transfer functionality
Receives emails from an email server, authenticate and transfer
Describe IMAP4
Internet Message Access Protocol version 4
TCP 143
Allows email clients to receive mail from a remote system, and you can change the status in the remote server. Keeps everything synced.
Manage email inbox from multiple clients
Describe LDAP
Lightweight Directory Access Protocol
TCP 389
Store and retrieve information in a network directory
Describe LDAPS
Lightweight Directory Access Protocol Secure
TCP 636
A non-standard implementation of LDAP over SSL
Describe H.323
Voice over IP (VoIP) signaling
TCP 1720
ITU Telecommunication H32x protocol seriies
Setup and manage VoIP sessions
One of the earliest VoIP standards, still used today.
Describe NetBIOS
NetBIOS
TCP 139
UDP 137
Network Basic Input/Output System.
Provides services allowing applications on separate computers to communicate over a LAN for file and printer sharing.
The _________________ command allows you to see every open port on a specific IP address.
nmap or zenmap
