1.4 Common Ports Flashcards
N10-009 Obj, 1.4 Explain common networking ports, protocols, services, and traffic types (23 cards)
What port does FTP use for control communication?
TCP port 21 — Used for sending control commands in the File Transfer Protocol.
File Transfer Protocol
* Not specific to an operating system
* Authenticates using username and password
* full-featured functionality (list, add, delete, etc.)
tcp/21
Sends and receives files between systems
What port does FTP use for data transfer?
File Transfer Protocol
* Not specific to an operating system
* Authenticates using username and password
* full-featured functionality (list, add, delete, etc.)
TCP port 20 — Used for transferring files between systems using FTP
tcp/20
Sends and receives files between systems
What port does SSH use?
Secure Shell
TCP port 22 — Used for secure remote login and command-line access.
tcp/22
Encrypted console login
What port does SFTP use?
Secure FTP
TCP port 22 — Secure File Transfer Protocol that uses SSH to encrypt file transfers.
Provides file system functionality
* Resuming interrupted transfers, directory listings, remote file removal
tcp/22
Encrypted file transfers using SSH
What port does Telnet use?
Telecommunication Network
TCP port 23 — Used for unencrypted remote command-line access.
Console access
* Similar functionality to SSH
* In-the-clear communication (not a good choice for production systems)
tcp/23
Remote console login to network devices
What port does SMTP use for unencrypted email transfer?
Simple Mail Transfer Protocol
TCP port 25 — Used for sending email messages between servers.
Also used to send mail from a device to a mail server
* Commonly configured on mobile devices and email clients
Other protocols are used for clients to receive email
* IMAP, POP3
tcp/25
Transfer email between mail servers
What port does SMTP use for encrypted email with TLS?
Simple Mail Transfer Protocol
TCP port 587 — Used for sending encrypted email messages with TLS.
Also used to send mail from a device to a mail server
* Commonly configured on mobile devices and email clients
Other protocols are used for clients to receive email
* IMAP, POP3
tcp/587
Transfer email between mail servers
What port does DNS use for most name resolution queries?
Domain Name System
UDP port 53 — Used for resolving domain names to IP addresses.
udp/53
Convert domain names to IP addresses
What port does DNS use for large data transfers?
Domain Name System
TCP port 53 — Used for DNS zone transfers and large queries.
tcp/53
Convert domain names to IP addresses
What ports does DHCP use?
Dynamic Host Configuration Protocol
UDP port 67 (server), UDP port 68 (client) — Used for automatic IP address assignment.
Automated configuration of IP address, subnet mask, and other options
* Requires DHCP server
* Server, appliance, integrated into a SOHO router, etc
Dynamic/pooled
* IP addresses are assigned in real-time from a pool
* Each system is given a lease, must renew at set intervals
DHCP Reservation
* Addresses are assigned by MAC address in the DHCP server
* Quickly manages addresses from one location
udp/67, udp/68
What port does TFTP use?
Trivial File Transfer Protocol
UDP port 69 — Used for simple, unauthenticated file transfers.
Very simple file transfer application
* Read files and write files
No authentication
* Not used on highly secure systems
Useful when starting a system
* Transfer configuration files
* Quick and easy
upd/69
What port does HTTP use?
Hypertext Transfer Protocol
TCP port 80 — Used for unencrypted web traffic.
Communication in the browser and by other applications
tcp/80
web server communication
What port does HTTPS use?
Secure HTTP
TCP port 443 — Used for encrypted web traffic using SSL/TLS.
tcp/443
web server communication
What port does NTP use?
Network Time Protocol
UDP port 123 — Used for synchronizing clocks between computer systems.
Switches, routers, firewalls, servers, workstations
* Every device has its own clock
Synchronizing the clocks is critical
* Log files, authentication information, outage details
Automatic updates
Flexible - you control how the clocks are updated
* Very accurate
* Accuracy is better than 1 millisecond on a local network
upd/123
Automatically synchronize clocks
What port does SNMP use for queries?
Simple Network Management Protocol
UDP port 161 — Used for collecting and organizing information about managed network devices.
V1 - The original
* Structured tables and data sent in-the-clear
V2 - A good step ahead
* Data type enhancements, bulk transfers
* Still in-the-clear
V3 - A secure standard
* Message integrity, authentication, encryption
udp/161
Gather statistics and manage network devices
What port does SNMP use for traps?
Simple Network Management Protocol
UDP port 162 — Used by devices to send alerts to a management station.
udp/162
Alerts and notifications from network devices
What port does LDAP use?
Lightweight Directory Access Protocol
TCP port 389 — Used for accessing and maintaining distributed directory information services.
tcp/389
Directory services
What port does LDAPS use?
Secure LDAP / LDAP Secure
TCP port 636 — Used for secure communication with LDAP directories.
A non-standard implementation of LDAP over SSL
tcp/636
Directory services
What port does SMB use in modern Windows systems?
Server Message Block (Microsoft Windows product)
TCP port 445 — Used for sharing files, printers, and other network resources.
Also called Common Internet File System (CIFS)
Integrated into the operating system
* Access rights integration across systems
* File share publishing
* File locking
tcp/445
File and printer sharing for Windows
What port does Syslog use?
System Logging
UDP port 514 — Used for sending system log or event messages to a central server.
Standard for message logging
* Diverse systems, consolidated log
Usually a central log collector
* Integrated into the SIEM
* Security information and Event Manager
You’re going to need alot of disk space
udp/514
A standard for message logging
What port does Microsoft SQL Server (MS-SQL) use?
TCP port 1433 — Used for querying and managing Microsoft SQL Server databases.
Databases
* Collection of information (many different types of data; one common method to store and query)
Structured Query Language (SQL)
* A standard language across database servers
SELECT * FROM Customers WHERE Last_Name='Messer'
tcp/1433
Microsoft’s structured query language database
What port does RDP use?
Remote Desktop Protocol
TCP port 3389 — Used for remote desktop access to Windows systems.
Connect to an entire desktop or just an application
Remote desktop services on many Windows versions
* Clients for Windows, MacOS, Linux, Unix, iPhone, and others
tcp/3389
Graphical display and control of a remote device
What ports does SIP use?
Session Initiation Protocol
TCP port 5060 (unencrypted), TCP port 5061 (encrypted) — Used to initiate, maintain, and terminate real-time communication sessions like VoIP.
Setup and manage VoIP sessions
* Call, ring, play busy tone, hang up
Extend voice communication
* Video conferencing
* Instant messaging
* File transfer
* etc.
tcp/5060, tcp/5061
Voice over IP signaling protocol
