Port Numbers Flashcards
RDP - Remote Desktop Protocol
port number
3389
RDP uses port 3389, and at each end the firewall must be adjusted to allow access through that port.
SSH (secure shell) port number
22
INFO: connection-oriented protocol used to set up secure Telnet connections for remote logins. SSH is secure and runs on port 22
File Transfer Protocol (FTP)
PORT NUMBER: 20, 21
INFO: used to manipulate files. FTP can copy files, list and manipulate directories, and view file contents. Port 21 is mainly used for file management and port 20 is used for data transfer. FTP is not secure and transmits in plain text.
Telnet
PORT NUMBER: 23
INFO: terminal emulation program that allows for remote access to text on another computer. Telnet is not secure and transmits plaintext.
Simple Mail Transfer Protocol (SMTP)
PORT NUMBER: 25.
INFO: used to send email only; a push protocol
DNS (Domain Name System)
PORT NUMBER: 53
INFO: used to resolve host names to IP addresses.
DHCP (Dynamic Host Configuration Protocol)
PORT NUMBER: 67/68
INFO: assigns IP addresses dynamically to network clients.
Port 67 - server.
Port 68 - client.
HTTP - Hypertext Transfer Protocol
PORT NUMBER: 80
INFO: manages connections between web server and client to view internet content
NOT secure and transmits in plain text.
POP3 - Post Office Protocol 3
used for downloading email
uses PORT NUMBER 110.
Network Basic Input/Output System (NetBIOS)/NetBIOS over TCP/IP (NetBT)
Network Basic Input/Output System (NetBIOS) is an API for communication between computers over a network. NetBIOS works over OSI layer 4 and needs to work with a layer 5 protocol, namely TCP/IP, to function properly. NetBIOS over TCP/IP is called NetBT.
NetBIOS runs on ports 137 AND 139.
IMAP (Internet Message Access Protocol)
used for downloading email; currently in 4th version (IMAP 4).
runs on PORT NUMBER 143.
SNMP (Simple Network Management Protocol)
used for network management.
Uses PORT NUMBERS 161 for sending and receiving requests and PORT 162 for receiving transmissions from managed devices.
LDAP (Lightweight Directory Access Protocol)
used for accessing information stored in an information directory.
PORT NUMBER: 389.
HTTPS (Hypertext Transfer Protocol Secure)
secure version of HTTP
uses PORT NUMBER 443
Server Message Block (SMB)/Common Internet File System (CIFS)
Server Message Block (SMB) is primarily a Microsoft protocol used for shared file access. Common Internet File System (CIFS) is an enhanced version of SMB.
SMB/CIFS use port 445.
Remote Desktop Protocol (RDP)
allows for remote connection to computers.
uses port 3389.
TCP (Transmission Control Protocol) vs. UDP (User Datagram Protocol)
Transmission Control Protocol (TCP) is a connection-oriented protocol used to send and receive data over a network. Before data is sent, a connection is established with the receiving host. It is considered a reliable protocol because the receiving host acknowledges that it received the data. TCP is used in cases where receiving the proper data is more important than speed.
User Datagram Protocol (UDP) is a connectionless protocol. Data is sent without any assurance that the receiving host is actually receiving the data. For that reason, it is considered an unreliable protocol. The advantage of UDP over TCP is that it is faster.
What are two connectionless protocols?
DHCP—Dynamic Host Configuration Protocol (DHCP) is used to dynamically assign IP configuration information to clients through a lease and uses UDP as its transport protocol. DHCP runs on port 67/68.
TFTP—Trivial File Transfer Protocol (TFTP) is a faster version of FTP that uses UDP rather than TCP as its transport protocol. TFTP uses port 69.
What are two connection oriented protocols?
HTTPS—Hypertext Transfer Protocol Secure (HTTPS) is a connection-oriented protocol that uses TCP as its transport protocol. HTTPS uses port 443.
SSH—Secure Shell (SSH) is a connection-oriented protocol that uses TCP as its transport protocol. SSH uses port 22.
