Common Port Numbers - 2.1 Flashcards
Compare and contrast Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) ports, protocols, and their purposes
Non-ephemeral ports
0 - 1,023
Ephemeral ports
1, 024 - 65, 535
FTP - file transfer protocol
tcp/20 (active mode) | tcp/21 (control)| Transfers files between systems
SSH (Secure shell)
tcp/22 | Encrypted communication link | looks and acts the same as Telnet
Telnet (Telecommunication Network)
tcp/23 | Login to devices remotely | Not the best choice for production systems (In-clear communication)
SMTP (Simple mail transfer protocol)
tcp/25 | Server to server email transfer | Also used to send mail | commonly configured on mobile devices and email | Receiving email: IMAP, POP3
DNS (Domain name system)
udp/53
DHCP (Dynamic host configuration protocol)
udp/67, udp/68 | Requires a DHCP server | server, appliance, integrated into a SOHO router
HTTP (Hypertext transfer protocol)
tcp/80 | webserver communication
HTTPS (Hypertext transfer protocol secure)
tcp/443 | webserver communication with encryption
POP3 (Post office protocol version 3)
tcp/110 | Receive emails from server
IMAP4 (Internet message access protocol version 4)
tcp/143 | Management of email inbox from multiple clients
SMB (Server message block)
Using NetBIOS over TCP/IP (Network Basic Input/output system) | udp/137 (NetBIOS name services (nbname) | tcp/139 (NetBIOS session service (nbsession) | File sharing, printer sharing | Also called CIFS (Common Internet File System) | tcp/445 (NetBIOS-less) | Direct SMB communication over TCP without the NetBIOS transport
SNMP (Simple Network Management Protocol)
udp/161 | Queries, udp/162 | Traps
LDAP (Lightweight Directory Access Protocol)
tcp/389 | Store and retrieve information in a network directory (Commonly used in Microsoft Active Directory)
