CompTIA Network Ports and Protocols

Cards · 50

Port 20 (FTP Data)

TCP. Transfers actual file data between client and server for File Transfer Protocol. Operates in plaintext.

Port 21 (FTP Control)

TCP. Handles commands and connection control for File Transfer Protocol. Operates in plaintext.

Port 22 (SSH / SFTP)

TCP. Secure Shell for encrypted terminal access and Secure FTP for encrypted file transfers. Encrypted.

Port 23 (Telnet)

TCP. Legacy unencrypted command-line remote management. Operates in plaintext.

Port 25 (SMTP)

TCP. Simple Mail Transfer Protocol used to send and relay email between servers. Operates in plaintext.

Port 53 (DNS)

UDP and TCP. Domain Name System resolves human-readable names to IP addresses. Operates in plaintext.

Port 67 (DHCP Server)

UDP. Dynamic Host Configuration Protocol server listener for client IP assignment requests. Operates in plaintext.

Port 68 (DHCP Client)

UDP. Dynamic Host Configuration Protocol client port receiving configuration from DHCP server. Operates in plaintext.

Port 69 (TFTP)

UDP. Trivial File Transfer Protocol used for simple, lightweight file transfers such as booting. Operates in plaintext.

Port 80 (HTTP)

TCP. Hypertext Transfer Protocol used for transmitting standard web traffic. Operates in plaintext.

Port 88 (Kerberos)

TCP and UDP. Network authentication protocol that uses ticket-granting services. Encrypted authentication tickets.

Port 110 (POP3)

TCP. Post Office Protocol v3 used by email clients to retrieve messages from a mail server. Operates in plaintext.

Port 123 (NTP)

UDP. Network Time Protocol used to synchronize computer system clocks over packet-switched networks. Operates in plaintext.

Port 135 (MS RPC)

TCP and UDP. Microsoft Remote Procedure Call endpoint mapper for client-server communication. Operates in plaintext.

Port 137 (NetBIOS Name Service)

UDP. NetBIOS Name Service provides name resolution for hosts on a local NetBIOS network. Operates in plaintext.

Port 138 (NetBIOS Datagram Service)

UDP. NetBIOS Datagram Service transmits connectionless datagram traffic on local subnets. Operates in plaintext.

Port 139 (NetBIOS Session Service)

TCP. NetBIOS Session Service establishes connection-oriented sessions between Windows systems. Operates in plaintext.

Port 143 (IMAP4)

TCP. Internet Message Access Protocol v4 enables email management directly on the mail server. Operates in plaintext.

Port 161 (SNMP Agent)

UDP. Simple Network Management Protocol used to query managed network devices. Plaintext in v1/v2c, encrypted in v3.

Port 162 (SNMP Trap)

UDP. Receives unsolicited notifications and alarm alerts from managed SNMP devices. Plaintext in v1/v2c, encrypted in v3.

Port 389 (LDAP)

TCP and UDP. Lightweight Directory Access Protocol queries and modifies directory services. Operates in plaintext.

Port 443 (HTTPS)

TCP. Hypertext Transfer Protocol Secure for encrypted web browsing via TLS/SSL. Encrypted.

Port 445 (SMB)

TCP. Server Message Block provides shared access to files, printers, and serial ports. Can be encrypted in modern SMB.

Port 465 (SMTPS)

TCP. Simple Mail Transfer Protocol over TLS/SSL for secure email submission. Encrypted.

Port 500 (ISAKMP / IKE)

UDP. Internet Security Association and Key Management Protocol used to establish IPsec VPNs. Encrypted key exchange.

Port 514 (Syslog)

UDP. Syslog protocol standard for collecting and sending system log messages. Operates in plaintext.

Port 587 (SMTP Submission)

TCP. Modern email client-to-server submission port utilizing opportunistic STARTTLS encryption. Plaintext or upgraded to encrypted.

Port 636 (LDAPS)

TCP. Lightweight Directory Access Protocol over TLS/SSL for secure directory queries. Encrypted.

Port 993 (IMAPS)

TCP. Internet Message Access Protocol over TLS/SSL for secure retrieval of email. Encrypted.

Port 995 (POP3S)

TCP. Post Office Protocol v3 over TLS/SSL for secure retrieval of email. Encrypted.

Port 1433 (MS SQL Server)

TCP. Default port for Microsoft SQL Server database engine client connections. Plaintext by default, supports encryption.

Port 1521 (Oracle Database)

TCP. Default listener port for Oracle database client connections. Plaintext by default, supports encryption.

Port 1701 (L2TP)

UDP. Layer 2 Tunneling Protocol used to support virtual private networks, typically paired with IPsec. Plaintext unless paired with IPsec.

Port 1720 (H.323)

TCP. ITU standard for setting up audio-visual communication sessions. Operates in plaintext.

Port 1723 (PPTP)

TCP. Point-to-Point Tunneling Protocol for legacy VPN connections. Encrypted with MPPE, considered insecure.

Port 1812 (RADIUS Authentication)

UDP. Remote Authentication Dial-In User Service port used for AAA authentication and authorization. Obfuscates passwords only.

Port 1813 (RADIUS Accounting)

UDP. Remote Authentication Dial-In User Service port used for tracking network resource consumption. Operates in plaintext.

Port 3306 (MySQL)

TCP. Default client connection port for MySQL and MariaDB databases. Plaintext by default, supports TLS.

Port 3389 (RDP)

TCP and UDP. Remote Desktop Protocol used by Microsoft Windows for GUI-based remote access. Encrypted.

Port 4500 (IPsec NAT-T)

UDP. NAT Traversal for IPsec enables VPN traffic to pass through Network Address Translation devices. Encrypted.

Port 5060 (SIP Plaintext)

TCP and UDP. Session Initiation Protocol used for signaling and controlling VoIP multimedia calls. Operates in plaintext.

Port 5061 (SIPS)

TCP. Session Initiation Protocol over TLS for encrypted VoIP signaling setup. Encrypted.

Port 5353 (mDNS)

UDP. Multicast DNS resolves hostnames to IP addresses within small networks without a local DNS server. Operates in plaintext.

Port 5432 (PostgreSQL)

TCP. Default listener port for PostgreSQL database client connections. Plaintext by default, supports TLS.

Port 6514 (Syslog over TLS)

TCP. Secure Syslog message transmission over Transport Layer Security. Encrypted.

Port 8080 (HTTP Alternate / Proxy)

TCP. Commonly used alternate port for web caching, proxies, or development web servers. Operates in plaintext.

Port 8443 (HTTPS Alternate)

TCP. Common alternative port for secure SSL/TLS web administration interfaces. Encrypted.

Port 49152–65535 (Dynamic/Ephemeral Ports)

TCP and UDP. Private dynamic port range allocated automatically for client-side outbound communication sessions. Security depends on application.

Port 49 (TACACS+)

TCP. Terminal Access Controller Access-Control System Plus provides centralized AAA security. Fully encrypted payload.

Port 88 (Kerberos AS/TGS)

UDP and TCP. Kerberos Authentication Service and Ticket Granting Service for single sign-on. Encrypted.