Search 200+ network port numbers commonly tested on CompTIA Security+, Network+, and A+ exams. Use the search bar to find ports by number, service name, or description.
203 results
| Port | Protocol | Service | Description | Exam |
|---|---|---|---|---|
| 20 | TCP | FTP Data | File Transfer Protocol data channel used for active-mode file transfers. | Security+Network+A+ |
| 21 | TCP | FTP Control | File Transfer Protocol control channel for commands and authentication (cleartext). | Security+Network+A+ |
| 22 | TCP | SSH / SCP / SFTP | Secure Shell for encrypted remote access, file copy (SCP) and file transfer (SFTP). | Security+Network+A+ |
| 23 | TCP | Telnet | Unencrypted remote terminal access; replaced by SSH due to security risks. | Security+Network+A+ |
| 25 | TCP | SMTP | Simple Mail Transfer Protocol for server-to-server email relay (cleartext by default). | Security+Network+A+ |
| 53 | Both | DNS | Domain Name System for resolving hostnames; uses UDP for queries and TCP for zone transfers. | Security+Network+A+ |
| 67 | UDP | DHCP Server | Dynamic Host Configuration Protocol server port for distributing IP addresses. | Security+Network+A+ |
| 68 | UDP | DHCP Client | Dynamic Host Configuration Protocol client port for receiving IP configuration. | Security+Network+A+ |
| 69 | UDP | TFTP | Trivial File Transfer Protocol for simple, unauthenticated file transfers (e.g. firmware, PXE boot). | Security+Network+A+ |
| 80 | TCP | HTTP | Hypertext Transfer Protocol for unencrypted web traffic. | Security+Network+A+ |
| 88 | Both | Kerberos | Kerberos authentication protocol used by Active Directory for ticket-based single sign-on. | Security+Network+ |
| 110 | TCP | POP3 | Post Office Protocol v3 for downloading email from a server (cleartext). | Security+Network+A+ |
| 111 | Both | RPCBind / SunRPC | Open Network Computing Remote Procedure Call port mapper used by NFS and other RPC services. | Network+ |
| 119 | TCP | NNTP | Network News Transfer Protocol for accessing Usenet newsgroups. | Network+ |
| 123 | UDP | NTP | Network Time Protocol for clock synchronisation across network devices. | Security+Network+A+ |
| 135 | TCP | MS-RPC / DCOM | Microsoft RPC Endpoint Mapper used for DCOM and remote service management. | Security+Network+A+ |
| 137 | UDP | NetBIOS Name | NetBIOS Name Service for name registration and resolution on Windows networks. | Security+Network+A+ |
| 138 | UDP | NetBIOS Datagram | NetBIOS Datagram Service for connectionless messaging on Windows networks. | Security+Network+A+ |
| 139 | TCP | NetBIOS Session | NetBIOS Session Service for connection-oriented file and printer sharing. | Security+Network+A+ |
| 143 | TCP | IMAP | Internet Message Access Protocol for server-side email management (cleartext). | Security+Network+A+ |
| 161 | UDP | SNMP | Simple Network Management Protocol for querying and managing network devices. | Security+Network+A+ |
| 162 | UDP | SNMP Trap | SNMP Trap port for receiving unsolicited alerts from managed devices. | Security+Network+A+ |
| 389 | Both | LDAP | Lightweight Directory Access Protocol for querying directory services like Active Directory. | Security+Network+A+ |
| 443 | TCP | HTTPS | HTTP over TLS/SSL for encrypted web traffic. | Security+Network+A+ |
| 445 | TCP | SMB / CIFS | Server Message Block for Windows file and printer sharing over TCP (no NetBIOS). | Security+Network+A+ |
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