Well-Known TCP/UDP Ports
- Ports 0 to 1023 are Well-Known Ports. These ports are assigned to a specific server sevice, eg, port 80 is used by web servers.
- Ports 1024 to 49151 are Registered Ports. These ports can be registered by developers to designate a particular port for their application.
- Ports 49152 to 65535 are Public Ports. When visiting a web site, the web browser will assign that session a port number from within this range.
When scanning, check for the following open ports:
- ftp: 21
- ssh: 22
- telnet: 23
- http: 80
- https: 443
- rlogin: 513
- rdp: 3389
- Status:
- ✅ Official
- ✓ Unofficial
- ❌ Conflict
| Port # | Protocol | Description | Status |
|---|---|---|---|
| 0 | TCP, UDP | Reserved; do not use (but is a permissible source port value if the sending process does not expect messages in response) | ✅ |
| 1 | TCP, UDP | TCPMUX | ✅ |
| 5 | TCP, UDP | RJE (Remote Job Entry) | ✅ |
| 7 | TCP, UDP | ECHO protocol | ✅ |
| 9 | TCP, UDP | DISCARD protocol / Wale-on-LAN (unofficial) | ✅ |
| 11 | TCP, UDP | SYSTAT protocol | ✅ |
| 13 | TCP, UDP | DAYTIME protocol | ✅ |
| 17 | TCP, UDP | QOTD (Quote of the Day) protocol | ✅ |
| 18 | TCP, UDP | Message Send Protocol | ✅ |
| 19 | TCP, UDP | CHARGEN (Character Generator) protocol | ✅ |
| 20 | TCP | FTP Protocol (data) - port for transferring FTP data | ✅ |
| 21 | TCP | FTP Protocol (control) - port for FTP commands and flow control | ✅ |
| 22 | TCP, UDP | SSH (Secure Shell) - used for secure logins, file transfers (scp, sftp) and port forwarding | ✅ |
| 23 | TCP, UDP | Telnet protocol - unencrypted text communication, remote login service | ✅ |
| 25 | TCP, UDP | SMTP (Simple Mail Transport Protocol) - used for email routing between email servers | ✅ |
| 26 | TCP, UDP | RSFTP - A simple FTP-like protocol | ✓ |
| 35 | TCP, UDP | QMS Magicolor 2 printer | ✓ |
| 37 | TCP, UDP | TIME protocol | ✅ |
| 38 | TCP, UDP | RAP (Route Access Protocol) | ✅ |
| 39 | TCP, UDP | RLP (Resource Location Protocol) | ✅ |
| 41 | TCP, UDP | Graphics | ✅ |
| 42 | TCP, UDP | Host Name Server/WINS Replications | ✅ |
| 43 | TCP | WHOIS protocol | ✅ |
| 49 | TCP, UDP | TACACS Login Host protocol | ✅ |
| 53 | TCP, UDP | DNS (Domain Name System) | ✅ |
| 57 | TCP | MTP, Mail Transfer Protocol | ✅ |
| 67 | UDP | BOOTP (BootStrap Protocol) server; also used by DHCP | ✅ |
| 68 | UDP | BOOTP (BootStrap Protocol) client; also used by DHCP | ✅ |
| 69 | UDP | TFTP (Trivial File Transfer Protocol) | ✅ |
| 70 | TCP | Gopher protocol | ✅ |
| 79 | TCP | Finger protocol | ✅ |
| 80 | TCP | HTTP (HyperText Transfer Protocol) - used for transferring web pages | ✅ |
| 81 | TCP | Torpark - Onion routing ORport | ✓ |
| 82 | UDP | Torpark - Control Port | ✓ |
| 88 | TCP | Kerberos - authenticating agent | ✅ |
| 101 | TCP | HOSTNAME | |
| 102 | TCP | ISO-TSAP protocol/Microsoft Exchange | |
| 107 | TCP | Remote Telnet Service | |
| 109 | TCP | POP, Post Office Protocol, version 2 | |
| 110 | TCP | POP3 (Post Office Protocol version 3) - used for retrieving emails | ✅ |
| 111 | TCP, UDP | SUNRPC protocol | |
| 113 | TCP | Ident - old server identification system, still used by IRC servers to identify its users | ✅ |
| 115 | TCP | SFTP, Simple File Transfer Protocol | |
| 117 | TCP | UUCP-PATH | |
| 118 | TCP, UDP | SQL Services | ✅ |
| 119 | TCP | NNTP (Network News Transfer Protocol) - used for retrieving newsgroups messages | ✅ |
| 123 | UDP | NTP (Network Time Protocol) - used for time synchronization | ✅ |
| 135 | TCP, UDP | EPMAP / Microsoft RPC Locator Service | ✅ |
| 137 | TCP, UDP | NetBIOS NetBIOS Name Service | ✅ |
| 138 | TCP, UDP | NetBIOS NetBIOS Datagram Service | ✅ |
| 139 | TCP, UDP | NetBIOS NetBIOS Session Service | ✅ |
| 143 | TCP, UDP | IMAP4 (Internet Message Access Protocol 4) - used for retrieving emails | ✅ |
| 152 | TCP, UDP | BFTP, Background File Transfer Program | |
| 153 | TCP, UDP | SGMP, Simple Gateway Monitoring Protocol | |
| 156 | TCP, UDP | SQL Service | ✅ |
| 157 | TCP, UDP | KNET VM Command Message Protocol | |
| 158 | TCP, UDP | DMSP, Distributed Mail Service Protocol | |
| 159 | TCP, UDP | NSS-Routing | |
| 160 | TCP, UDP | SGMP-TRAPS | |
| 161 | TCP, UDP | SNMP (Simple Network Management Protocol) | ✅ |
| 162 | TCP, UDP | SNMPTRAP | ✅ |
| 170 | TCP | Print-srv | |
| 179 | TCP | BGP (Border Gateway Protocol) - an exterior gateway routing protocol that enables groups of routers to share routing information to ensure efficient and loop-free routes can be established. BGP is commonly used within and between ISPs. | ✅ |
| 190 | TCP, UDP | Gateway Access Control Protocol (GACP) | |
| 191 | TCP, UDP | Prospero Directory Service | |
| 192 | TCP, UDP | OSU Network Monitoring System, Apple AirPort Base Station PPP status or discovery, AirPort Admin Utility or Express Assistant | |
| 192 | TCP. UDP | SRMP (Spider Remote Monitoring Protocol) | |
| 194 | TCP | IRC (Internet Relay Chat) | ✅ |
| 201 | TCP, UDP | AppleTalk Routing Maintenance | |
| 209 | TCP, UDP | The Quick Mail Transfer Protocol | |
| 213 | TCP, UDP | IPX | ✅ |
| 218 | TCP, UDP | MPP, Message Posting Protocol | |
| 220 | TCP, UDP | IMAP, Interactive Mail AccessProtocol, version 3 | |
| 259 | TCP, UDP | ESRO, Efficient Short Remote Operations | |
| 264 | TCP, UDP | BGMP, Border Gateway Multicast Protocol | |
| 311 | TCP | Apple Server-Admin-Tool, Workgroup-Manager-Tool | |
| 318 | TCP, UDP | TSP, Time Stamp Protocol | |
| 323 | TCP, UDP | IMMP, Internet Message Mapping Protocol | |
| 366 | TCP, UDP | SMTP, Simple Mail Transfer Protocol. On-Demand Mail Relay (ODMR) | |
| 369 | TCP, UDP | Rpc2portmap | ✅ |
| 371 | TCP, UDP | ClearCase albd | ✅ |
| 383 | TCP, UDP | HP OpenView HTTPs Operations Agent | |
| 384 | TCP, UDP | A Remote Network Server System | |
| 387 | TCP, UDP | AURP, AppleTalk Update-Based Routing Protocol | |
| 389 | TCP, UDP | LDAP (Lightweight Directory Access Protocol) | ✅ |
| 401 | TCP, UDP | UPS Uninterruptible Power Supply | ✅ |
| 411 | TCP | Direct Connect Hub port | ✓ |
| 427 | TCP, UDP | SLP (Service Location Protocol) | ✅ |
| 443 | TCP | HTTPS - HTTP Protocol over TLS/SSL (used for transferring web pages securely using encryption) | ✅ |
| 444 | TCP, UDP | SNPP, Simple Network Paging Protocol | |
| 445 | TCP | Microsoft-DS (Active Directory, Windows shares, Sasser worm, Agobot, Zobotworm) | ✅ |
| 445 | UDP | Microsoft-DS SMB file sharing | ✅ |
| 464 | TCP, UDP | Kerberos Change/Set password | ✅ |
| 465 | TCP | SMTP over SSL - CONFLICT with registered Cisco protocol | ❌ |
| 500 | TCP, UDP | ISAKMP, IKE-Internet Key Exchange | ✅ |
| 512 | TCP | exec, Remote Process Execution | |
| 512 | UDP | comsat, together with biff: notifies users of new c.q. yet unread e-mail | |
| 513 | TCP | Login | |
| 513 | UDP | Who | |
| 514 | TCP | rsh protocol - used to execute non-interactive commandline commands on a remote system and see the screen return | |
| 514 | UDP | syslog protocol - used for system logging | ✅ |
| 515 | TCP | Line Printer Daemon protocol - used in LPD printer servers | |
| 517 | TCP | Talk | |
| 518 | UDP | NTalk | |
| 520 | TCP | efs | |
| 520 | UDP | Routing - RIP | ✅ |
| 513 | UDP | Router | |
| 524 | TCP, UDP | NCP (NetWare Core Protocol) is used for a variety things such as access to primary NetWare server resources, Time Synchronization, etc. | ✅ |
| 525 | UDP | Timed, Timeserver | |
| 530 | TCP, UDP | RPC | ✅ |
| 531 | TCP, UDP | AOL Instant Messenger, IRC | |
| 532 | TCP | netnews | |
| 533 | UDP | netwall, For Emergency Broadcasts | |
| 540 | TCP | UUCP (Unix-to-Unix Copy Protocol) | |
| 542 | TCP, UDP | commerce (Commerce Applications) | |
| 543 | TCP | klogin, Kerberos login | |
| 544 | TCP | kshell, Kerberos Remote Shell | |
| 546 | TCP, UDP | DHCPv6 client | |
| 547 | TCP, UDP | DHCPv6 server | |
| 548 | TCP | AFP (Apple Filing Protocol) | |
| 550 | UDP | new-rwho, new-who | |
| 554 | TCP, UDP | RTSP (Real Time Streaming Protocol) | ✅ |
| 556 | TCP | Remotefs, rfs, rfs_server | |
| 560 | UDP | rmonitor, Remote Monitor | |
| 561 | UDP | monitor | |
| 561 | TCP, UDP | chcmd | |
| 563 | TCP, UDP | NNTP protocol over TLS/SSL (NNTPS) | ✅ |
| 587 | TCP | Email message submission (SMTP) (RFC 2476) | ✅ |
| 591 | TCP | FileMaker 6.0 Web Sharing (HTTP Alternate, see port 80) | ✅ |
| 593 | TCP, UDP | HTTP RPC Ep Map/Microsoft DCOM | ✅ |
| 604 | TCP | TUNNEL | |
| 631 | TCP, UDP | IPP, Internet Printing Protocol | |
| 636 | TCP, UDP | LDAP over SSL (encrypted transmission) | ✅ |
| 639 | TCP, UDP | MSDP, Multicast Source Discovery Protocol | |
| 646 | TCP | LDP, Label Distribution Protocol | |
| 647 | TCP | DHCP Failover Protocol | |
| 648 | TCP | RRP, Registry Registrar Protocol | |
| 652 | TCP | DTCP, Dynamic Tunnel Configuration Protocol | |
| 654 | TCP | AODV, Ad hoc On-Demand Distance Vector | |
| 665 | TCP | sun-dr, Remote Dynamic Reconfiguration | ✓ |
| 666 | UDP | Doom, First online FPS | |
| 674 | TCP | ACAP, Application Configuration Access Protocol | |
| 691 | TCP | Microsoft Exchange Routing | ✅ |
| 692 | TCP | Hyperwave-ISP | |
| 695 | TCP | IEEE-MMS-SSL | |
| 698 | TCP | OLSR, Optimized Link State Routing | |
| 699 | TCP | Access Network | |
| 700 | TCP | EPP, Extensible Provisioning Protocol | |
| 701 | TCP | LMP, Link Management Protocol. | |
| 702 | TCP | IRIS over BEEP | |
| 706 | TCP | SILC, Secure Internet Live Conferencing | |
| 711 | TCP | TDP, Tag Distribution Protocol | |
| 712 | TCP | TBRPF, Topology Broadcast based on Reverse-Path Forwarding | |
| 720 | TCP | SMQP, Simple Message Queue Protocol | |
| 749 | TCP, UDP | kerberos-adm, Kerberos administration | |
| 750 | UDP | Kerberos version IV | |
| 782 | TCP | Conserver serial-console management server | |
| 829 | TCP | CMP (Certificate Management Protocol) | |
| 860 | TCP | iSCSI | |
| 873 | TCP | rsync - File synchronisation protocol | ✅ |
| 901 | TCP | Samba Web Administration Tool (SWAT) | ✓ |
| 902 | VMware Server | ✓ | |
| 911 | TCP | Network Console on Acid (NCA) - local tty redirection over OpenSSH | |
| 981 | TCP | SofaWare Technologies Remote HTTPS management for firewall devices running embedded Checkpoint Firewall-1 software | ✓ |
| 989 | TCP, UDP | FTP Protocol (data) over TLS/SSL | ✅ |
| 990 | TCP, UDP | FTP Protocol (control) over TLS/SSL | ✅ |
| 991 | TCP, UDP | NAS (Netnews Admin System) | |
| 992 | TCP, UDP | Telnet protocol over TLS/SSL | ✅ |
| 993 | TCP | IMAP4 over SSL (encrypted transmission) | ✅ |
| 995 | TCP | POP3 over SSL (encrypted transmission) | ✅ |