Ports Flashcards Preview

CompTIA A+ Core 1 > Ports > Flashcards

Flashcards in Ports Deck (40)
Loading flashcards...
1

FTP

20/21

File Transfer Protocol
• tcp/20 (active mode data), tcp/21 (control)
• Transfers files between systems
• Authenticates with a username and password
• Some systems use a generic/anonymous login
• Full-featured functionality
• List, add, delete, etc.

2

SSH

22

Secure Shell
• Encrypted communication link - tcp/22
• Looks and acts the same as Telnet

3

Telnet

23

• Telnet – Telecommunication Network - tcp/23
• Login to devices remotely
• Console access
• In-the-clear communication
• Not the best choice for production systems

4

SMTP

25

Simple Mail Transfer Protocol
• Server to server email transfer - tcp/25
• 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

5

DNS

53

Domain Name System
• Converts names to IP addresses - udp/53
• www.professormesser.com = 162.159.246.164
• These are very critical resources
• Usually multiple DNS servers are in production

6

HTTP

80

Hypertext Transfer Protocol - tcp/80
• Communication in the browser
• And by other applications

7

HTTPS

443

Hypertext Transfer Protocol Secure
• Encrypted - HTTPS - tcp/443
• Supported by nearly all web servers and clients

8

POP3

110

• POP3 - Post office Protocol version 3 - tcp/110
• Basic mail transfer functionality
• Receive emails from an email server
• Authenticate and transfer

9

IMAP4

143

Internet Message Access Protocol v4 - tcp/143
• Includes management of email inbox from multiple clients

10

RDP

3389

Remote Desktop Protocol
• Share a desktop from a remote location over tcp/3389
• Remote Desktop Services on many Windows versions
• Can connect to an entire desktop or just an application
• Clients for Windows, macOS, Linux, Unix,
iPhone, Android, and others

11

NETBIOS

137, 138, 139

Server Message Block
• Protocol used by Microsoft Windows
• File sharing, printer sharing
• Also called CIFS (Common Internet File System)
• Using NetBIOS over TCP/IP
• udp/137 - NetBIOS name services (nbname)
• udp/138 - NetBIOS datagram service (nbdatagram)
• tcp/139 - NetBIOS session service (nbsession)

12

AFP

548

Apple Filing Protocol
• File services in macOS
• tcp/548
• Works with SLP (Service Location Protocol)
• tcp/427 and udp/427
• Populates the list of available devices
• File management
• Copy, move, delete files

13

DHCP

67, 68

Dynamic Host Configuration Protocol
• Automated configuration of IP address, subnet mask
and other options
• udp/67, udp/68
• Requires a 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 and must renew
at set intervals
• DHCP reservation
• Addresses are assigned by MAC address
in the DHCP server
• Quickly manage addresses from one location

14

LDAP

389

Lightweight Directory Access Protocol
• tcp/389
• Store and retrieve information in a network directory
• Commonly used in Microsoft Active Directory

15

SNMP

161, 162

Simple Network Management Protocol
• Gather statistics from network devices
• Queries: udp/161
• Traps: udp/162
• v1 – The original
• Structured tables, 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

16

20/21

FTP

File Transfer Protocol
• tcp/20 (active mode data), tcp/21 (control)
• Transfers files between systems
• Authenticates with a username and password
• Some systems use a generic/anonymous login
• Full-featured functionality
• List, add, delete, etc.

17

22

SSH

Secure Shell
• Encrypted communication link - tcp/22
• Looks and acts the same as Telnet

18

23

Telnet

• Telnet – Telecommunication Network - tcp/23
• Login to devices remotely
• Console access
• In-the-clear communication
• Not the best choice for production systems

19

25

SMTP

Simple Mail Transfer Protocol
• Server to server email transfer - tcp/25
• 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

20

53

DNS

Domain Name System
• Converts names to IP addresses - udp/53
• www.professormesser.com = 162.159.246.164
• These are very critical resources
• Usually multiple DNS servers are in production

21

80

HTTP

Hypertext Transfer Protocol - tcp/80
• Communication in the browser
• And by other applications

22

110

POP3

• Post office Protocol version 3 - tcp/110
• Basic mail transfer functionality
• Receive emails from an email server
• Authenticate and transfer

23

143

IMAP

Internet Message Access Protocol v4 - tcp/143
• Includes management of email inbox from multiple clients

24

443

HTTPS

Hypertext Transfer Protocol Secure
• Encrypted - HTTPS - tcp/443
• Supported by nearly all web servers and clients

25

3389

RDP

Remote Desktop Protocol
• Share a desktop from a remote location over tcp/3389
• Remote Desktop Services on many Windows versions
• Can connect to an entire desktop or just an application
• Clients for Windows, macOS, Linux, Unix, iPhone, Android, and others

26

137–139

NETBIOS

• Protocol used by Microsoft Windows
• File sharing, printer sharing
• Also called CIFS (Common Internet File System)
• Using NetBIOS over TCP/IP
• udp/137 - NetBIOS name services (nbname)
• udp/138 - NetBIOS datagram service (nbdatagram)
• tcp/139 - NetBIOS session service (nbsession)

27

445

SMB/CIFS

CIFS
Common Internet File System (CIFS) is a Microsoft-developed enhancement of the SMB protocol, which was also developed by Microsoft. The intent behind CIFS is that it can be used to share files and printers between computers, regardless of the operating system that they run. It’s been the default file and print sharing protocol on Windows-based computers since Windows 2000.

SMB
Server Message Block (SMB) is a protocol originally developed by IBM but then enhanced by Microsoft, IBM, Intel, and others. It’s used to provide shared access to files, printers, and other network resources and is primarily implemented by Microsoft systems. In a way, it can function a bit like FTP only with a few more options, such as the ability to connect to printers, and more management commands. It’s also known for its ability to make network resources easily visible through various Windows network apps (such as Network in File Explorer).

28

427

SLP

The Service Location Protocol (SLP) is a non-proprietary protocol designed to help locate resources on a network. Without protocols such as SLP (and SMB), users wanting to access networked resources need to enter the hostname or IP address of the machine that provides the resource. SLP makes the resources visible and therefore easy to connect to.

SLP was developed by the Internet Engineering Task Force (IETF), so it’s considered an industry standard. The advantage is that it can be used with non-Microsoft operating systems, such as macOS and Linux.

29

548

AFP

Apple Filing Protocol
• File services in macOS
• tcp/548
• Works with SLP (Service Location Protocol)
• tcp/427 and udp/427
• Populates the list of available devices
• File management
• Copy, move, delete files

30

67/68

DHCP

Dynamic Host Configuration Protocol
• Automated configuration of IP address, subnet mask
and other options
• udp/67, udp/68
• Requires a 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 and must renew
at set intervals
• DHCP reservation
• Addresses are assigned by MAC address
in the DHCP server
• Quickly manage addresses from one location