0-1023
| Port | Description | Status |
| 0/TCP,UDP | Reserved | Official |
| 1/TCP,UDP | | Official |
| 2/TCP,UDP | Management Utility | Official |
| 3/TCP,UDP | Compression Process | Official |
| 5/TCP,UDP | Remote Job Entry | Official |
| 7/TCP,UDP | Echo | Official |
| 9/TCP,UDP | Discard | Official |
| 11/TCP,UDP | Active Users | Official |
| 13/TCP,UDP | DAYTIME – (RFC 867) | Official |
| 17/TCP,UDP | Quote of the Day | Official |
| 18/TCP,UDP | Message Send Protocol | Official |
| 19/TCP,UDP | Character Generator | Official |
| 20/TCP | FTP – data | Official |
| 21/TCP | FTP—control (command) | Official |
| 22/TCP,UDP | Secure Shell (SSH)—used for secure logins, file transfers (scp, sftp) and port forwarding | Official |
| 23/TCP | Telnet protocol—unencrypted text communications | Official |
| 25/TCP | Simple Mail Transfer Protocol (SMTP)—used for e-mail routing between mail servers | Official |
| 34/TCP,UDP | Remote File (RF)—used to transfer files between machines | Unofficial |
| 35/TCP,UDP | Any private printer server protocol | Official |
| 35/TCP,UDP | QMS Magicolor 2 printer server protocol | Unofficial |
| 37/TCP,UDP | TIME protocol | Official |
| 39/TCP,UDP | Resource Location Protocol[2] (RLP)—used for determining the location of higher level services from hosts on a network | Official |
| 41/TCP,UDP | Graphics | Official |
| 42/TCP,UDP | nameserver, ARPA Host Name Server Protocol | Official |
| 42/TCP,UDP | WINS | Unofficial |
| 43/TCP | WHOIS protocol | Official |
| 49/TCP,UDP | TACACS aka TACOS Login Host protocol | Official |
| 52/TCP,UDP | XNS (Xerox Network Services) Time Protocol | Official |
| 53/TCP,UDP | Domain Name System (DNS) | Official |
| 54/TCP,UDP | XNS (Xerox Network Services) Clearinghouse | Official |
| 55/TCP,UDP | ISI-GL (ISI Graphics Language) | Unofficial |
| 56/TCP,UDP | XNS (Xerox Network Services) Authentication | Official |
| 56/TCP,UDP | RAP (Route Access Protocol)[3] | Unofficial |
| 57/TCP | MTP, Mail Transfer Protocol | Unofficial |
| 58/TCP,UDP | XNS (Xerox Network Services) Mail | Official |
| 67/UDP | Bootstrap Protocol (BOOTP) Server; also used by Dynamic Host Configuration Protocol (DHCP) | Official |
| 68/UDP | Bootstrap Protocol (BOOTP) Client; also used by Dynamic Host Configuration Protocol (DHCP) | Official |
| 69/UDP | Trivial File Transfer Protocol (TFTP) | Official |
| 70/TCP | Gopher protocol | Official |
| 79/TCP | Finger protocol | Official |
| 80/TCP,UDP | Hypertext Transfer Protocol (HTTP) | Official |
| 81/TCP | Torpark—Onion routing | Unofficial |
| 82/UDP | Torpark—Control | Unofficial |
| 83/TCP | MIT ML Device | Official |
| 88/TCP,UDP | Kerberos—authentication system | Official |
| 90/TCP,UDP | dnsix (DoD Network Security for Information Exchange) Securit Attribute Token Map | Official |
| 90/TCP,UDP | Pointcast | Unofficial |
| 99/TCP | WIP Message Protocol | Unofficial |
| 101/TCP | NIC host name | Official |
| 102/TCP | ISO-TSAP (Transport Service Access Point) Class 0 protocol[4] | Official |
| 104/TCP,UDP | ACR/NEMA Digital Imaging and Communications in Medicine | Official |
| 107/TCP | Remote TELNET Service[5] protocol | Official |
| 109/TCP | Post Office Protocol 2 (POP2) | Official |
| 110/TCP | Post Office Protocol 3 (POP3) | Official |
| 111/TCP,UDP | Sun Remote Procedure Call | Official |
| 113/UDP | ident—user identification system, used by IRC servers to identify users | Official |
| 113/TCP,UDP | Authentication Service (auth) | Official |
| 115/TCP | Simple File Transfer Protocol (SFTP) | Official |
| 117/TCP | UUCP Path Service | Official |
| 118/TCP,UDP | SQL (Structured Query Language) Services | Official |
| 119/TCP | Network News Transfer Protocol (NNTP)—used for retrieving newsgroup messages | Official |
| 123/UDP | Network Time Protocol (NTP)—used for time synchronization | Official |
| 135/TCP,UDP | DCE endpoint resolution | Official |
| 135/TCP,UDP | Microsoft EPMAP (End Point Mapper), also known as DCE/RPC Locator service[6], used to remotely manage services including DHCP server, DNS server and WINS. Also used by DCOM | Unofficial |
| 137/TCP,UDP | NetBIOS NetBIOS Name Service | Official |
| 138/TCP,UDP | NetBIOS NetBIOS Datagram Service | Official |
| 139/TCP,UDP | NetBIOS NetBIOS Session Service | Official |
| 143/TCP,UDP | Internet Message Access Protocol (IMAP)—used for retrieving, organizing, and synchronizing e-mail messages | Official |
| 152/TCP,UDP | Background File Transfer Program (BFTP)[7] | Official |
| 153/TCP,UDP | SGMP, Simple Gateway Monitoring Protocol | Official |
| 156/TCP,UDP | SQL Service | Official |
| 158/TCP,UDP | DMSP, Distributed Mail Service Protocol | Unofficial |
| 161/TCP,UDP | Simple Network Management Protocol (SNMP) | Official |
| 162/TCP,UDP | Simple Network Management Protocol Trap (SNMPTRAP)[8] | Official |
| 170/TCP | Print-srv, Network PostScript | Official |
| 177/TCP,UDP | X Display Manager Control Protocol (XDMCP) | Official |
| 179/TCP | BGP (Border Gateway Protocol) | Official |
| 194/TCP,UDP | IRC (Internet Relay Chat) | Official |
| 199/TCP,UDP | SMUX, SNMP Unix Multiplexer | Official |
| 201/TCP,UDP | AppleTalk Routing Maintenance | Official |
| 209/TCP,UDP | The Quick Mail Transfer Protocol | Official |
| 213/TCP,UDP | IPX | Official |
| 218/TCP,UDP | MPP, Message Posting Protocol | Official |
| 220/TCP,UDP | IMAP, Interactive Mail Access Protocol, version 3 | Official |
| 259/TCP,UDP | ESRO, Efficient Short Remote Operations | Official |
| 264/TCP,UDP | BGMP, Border Gateway Multicast Protocol | Official |
| 311/TCP | Mac OS X Server Admin (officially AppleShare IP Web administration) | Official |
| 308/TCP | Novastor Online Backup | Official |
| 318/TCP,UDP | PKIX TSP, Time Stamp Protocol | Official |
| 323/TCP,UDP | IMMP, Internet Message Mapping Protocol | Unofficial |
| 350/TCP,UDP | MATIP-Type A, Mapping of Airline Traffic over Internet Protocol | Official |
| 351/TCP,UDP | MATIP-Type B, Mapping of Airline Traffic over Internet Protocol | Official |
| 366/TCP,UDP | ODMR, On-Demand Mail Relay | Official |
| 369/TCP,UDP | Rpc2portmap | Official |
| 370/TCP,UDP | codaauth2 – Coda authentication server | Unofficial |
| 370/TCP,UDP | securecast1 – Outgoing packets to NAI's servers, http://www.nai.com/asp_set/anti_virus/alerts/faq.as | Unofficial |
| 371/TCP,UDP | ClearCase albd | Official |
| 383/TCP,UDP | HP data alarm manager | Official |
| 384/TCP,UDP | A Remote Network Server System | Official |
| 387/TCP,UDP | AURP, AppleTalk Update-based Routing Protocol | Official |
| 389/TCP,UDP | Lightweight Directory Access Protocol (LDAP) | Official |
| 401/TCP,UDP | UPS Uninterruptible Power Supply | Official |
| 402/TCP | Altiris, Altiris Deployment Client | Unofficial |
| 411/TCP | Direct Connect Hub | Unofficial |
| 412/TCP | Direct Connect Client-to-Client | Unofficial |
| 427/TCP,UDP | Service Location Protocol (SLP) | Official |
| 443/TCP,UDP | Hypertext Transfer Protocol over TLS/SSL (HTTPS) | Official |
| 444/TCP,UDP | SNPP, Simple Network Paging Protocol (RFC 1568) | Official |
| 445/TCP | Microsoft-DS Active Directory, Windows shares | Official |
| 445/UDP | Microsoft-DS SMB file sharing | Official |
| 464/TCP,UDP | Kerberos Change/Set password | Official |
| 465/TCP | Cisco protocol | Unofficial |
| 465/TCP | SMTP over SSL | Unofficial |
| 475/TCP | tcpnethaspsrv (Hasp services, TCP/IP version) | Official |
| 497/TCP | Dantz Retrospect | Official |
| 500/UDP | Internet Security Association and Key Management Protocol (ISAKMP) | Official |
| 501/TCP | STMF, Simple Transportation Management Framework – DOT NTCIP 1101 | Unofficial |
| 502/TCP,UDP | Modbus, Protocol | Unofficial |
| 504/TCP,UDP | Citadel – multiservice protocol for dedicated clients for the Citadel groupware system | Official |
| 510/TCP | First Class Protocol | Unofficial |
| 512/TCP | Rexec, Remote Process Execution | Official |
| 512/UDP | comsat, together with biff | Official |
| 513/TCP | Login | Official |
| 513/UDP | Who | Official |
| 514/TCP | Shell—used to execute non-interactive commands on a remote system | Official |
| 514/UDP | Syslog—used for system logging | Official |
| 515/TCP | Line Printer Daemon—print service | Official |
| 517/UDP | Talk | Official |
| 518/UDP | NTalk | Official |
| 520/TCP | efs, extended file name server | Official |
| 520/UDP | Routing—RIP | Official |
| 524/TCP,UDP | NCP (NetWare Core Protocol) is used for a variety things such as access to primary NetWare server resources, Time Synchronization, etc. | Official |
| 525/UDP | Timed, Timeserver | Official |
| 530/TCP,UDP | RPC | Official |
| 531/TCP,UDP | AOL Instant Messenger, IRC | Unofficial |
| 532/TCP | netnews | Official |
| 533/UDP | netwall, For Emergency Broadcasts | Official |
| 540/TCP | UUCP (Unix-to-Unix Copy Protocol) | Official |
| 542/TCP,UDP | commerce (Commerce Applications) | Official |
| 543/TCP | klogin, Kerberos login | Official |
| 544/TCP | kshell, Kerberos Remote shell | Official |
| 546/TCP,UDP | DHCPv6 client | Official |
| 547/TCP,UDP | DHCPv6 server | Official |
| 548/TCP | Apple Filing Protocol (AFP) over TCP | Official |
| 550/UDP | new-rwho, new-who | Official |
| 554/TCP,UDP | Real Time Streaming Protocol (RTSP) | Official |
| 556/TCP | Remotefs, RFS, rfs_server | Official |
| 560/UDP | rmonitor, Remote Monitor | Official |
| 561/UDP | monitor | Official |
| 563/TCP,UDP | NNTP protocol over TLS/SSL (NNTPS) | Official |
| 587/TCP | e-mail message submission[9] (SMTP) | Official |
| 591/TCP | FileMaker 6.0 (and later) Web Sharing (HTTP Alternate, also see port 80) | Official |
| 593/TCP,UDP | HTTP RPC Ep Map, Remote procedure call over Hypertext Transfer Protocol, often used by Distributed Component Object Model services and Microsoft Exchange Server | Official |
| 604/TCP | TUNNEL profile[10], a protocol for BEEP peers to form an application layer tunnel | Official |
| 623/UDP | ASF Remote Management and Control Protocol (ASF-RMCP) | Official |
| 631/TCP,UDP | Internet Printing Protocol (IPP) | Official |
| 636/TCP,UDP | Lightweight Directory Access Protocol over TLS/SSL (LDAPS) | Official |
| 639/TCP,UDP | MSDP, Multicast Source Discovery Protocol | Official |
| 641/TCP,UDP | SupportSoft Nexus Remote Command (control/listening): A proxy gateway connecting remote control traffic | Official |
| 646/TCP,UDP | LDP, Label Distribution Protocol, a routing protocol used in MPLS networks | Official |
| 647/TCP | DHCP Failover protocol[11] | Official |
| 648/TCP | RRP (Registry Registrar Protocol)[12] | Official |
| 652/TCP | DTCP, Dynamic Tunnel Configuration Protocol | Unofficial |
| 653/TCP,UDP | SupportSoft Nexus Remote Command (data): A proxy gateway connecting remote control traffic | Official |
| 654/TCP | AODV (Ad-hoc On-demand Distance Vector) | Official |
| 655/TCP | IEEE MMS (IEEE Media Management System)[13][14] | Official |
| 657/TCP,UDP | IBM RMC (Remote monitoring and Control) protocol, used by System p5 AIX Integrated Virtualization Manager (IVM)[15] and Hardware Management Console to connect managed logical partitions (LPAR) to enable dynamic partition reconfiguration | Official |
| 660/TCP | Mac OS X Server administration | Official |
| 665/TCP | sun-dr, Remote Dynamic Reconfiguration | Unofficial |
| 666/UDP | Doom, first online first-person shooter | Official |
| 674/TCP | ACAP (Application Configuration Access Protocol) | Official |
| 691/TCP | MS Exchange Routing | Official |
| 692/TCP | Hyperwave-ISP | Official |
| 694/UDP | Linux-HA High availability Heartbeat | Unofficial |
| 695/TCP | IEEE-MMS-SSL (IEEE Media Management System over SSL)[16] | Official |
| 698/UDP | OLSR (Optimized Link State Routing) | Official |
| 699/TCP | Access Network | Official |
| 700/TCP | EPP (Extensible Provisioning Protocol), a protocol for communication between domain name registries and registrars (RFC 4934) | Official |
| 701/TCP | LMP (Link Management Protocol (Internet))[17], a protocol that runs between a pair of nodes and is used to manage traffic engineering (TE) links | Official |
| 702/TCP | IRIS[18][19] (Internet Registry Information Service) over BEEP (Blocks Extensible Exchange Protocol)[20] (RFC 3983) | Official |
| 706/TCP | SILC, Secure Internet Live Conferencing | Official |
| 711/TCP | Cisco TDP, Tag Distribution Protocol[21][22][23]—being replaced by the MPLS Label Distribution Protocol[24] | Official |
| 712/TCP | TBRPF, Topology Broadcast based on Reverse-Path Forwarding routing protocol (RFC 3684) | Official |
| 712/UDP | Promise RAID Controller | Unofficial |
| 720/TCP | SMQP, Simple Message Queue Protocol | Unofficial |
| 749/TCP,UDP | Kerberos administration | Official |
| 750/TCP | rfile | Official |
| 750/UDP | loadav | Official |
| 750/UDP | kerberos-iv, Kerberos version IV | Official |
| 751/TCP,UDP | pump | Official |
| 751/TCP,UDP | kerberos_master, Kerberos authentication | Unofficial |
| 752/TCP | qrh | Official |
| 752/UDP | qrh | Official |
| 752/UDP | userreg_server, Kerberos Password (kpasswd) server | Unofficial |
| 753/TCP | Reverse Routing Header (rrh)[25] | Official |
| 753/UDP | Reverse Routing Header (rrh) | Official |
| 753/UDP | passwd_server, Kerberos userreg server | Unofficial |
| 754/TCP | tell send | Official |
| 754/TCP | krb5_prop, Kerberos v5 slave propagation | Unofficial |
| 754/UDP | tell send | Official |
| 760/TCP,UDP | ns | Official |
| 760/TCP,UDP | krbupdate [kreg], Kerberos registration | Unofficial |
| 782/TCP | Conserver serial-console management server | Unofficial |
| 783/TCP | SpamAssassin spamd daemon | Unofficial |
| 829/TCP | CMP (Certificate Management Protocol) | Unofficial |
| 843/TCP | Adobe Flash socket policy server | Unofficial |
| 860/TCP | iSCSI (RFC 3720) | Official |
| 873/TCP | rsync file synchronisation protocol | Official |
| 888/TCP | cddbp, CD DataBase (CDDB) protocol (CDDBP)—unassigned but widespread use | Unofficial |
| 901/TCP | Samba Web Administration Tool (SWAT) | Unofficial |
| 901/TCP, UDP | VMware Virtual Infrastructure Client (UDP from server being managed to management console) | Unofficial |
| 902/TCP | VMware Server Console (TCP from management console to server being Managed) | Unofficial |
| 902/UDP | VMware Server Console (UDP from server being managed to management console) | Unofficial |
| 903/TCP | VMware Remote Console [26] | Unofficial |
| 904/TCP | VMware Server Alternate (if 902 is in use, i.e. SUSE linux) | Unofficial |
| 911/TCP | Network Console on Acid (NCA)—local tty redirection over OpenSSH | Unofficial |
| 953/TCP,UDP | Domain Name System (DNS) RDNC Service | Unofficial |
| 981/TCP | SofaWare Technologies Remote HTTPS management for firewall devices running embedded Check Point FireWall-1 software | Unofficial |
| 989/TCP,UDP | FTPS Protocol (data): FTP over TLS/SSL | Official |
| 990/TCP,UDP | FTPS Protocol (control): FTP over TLS/SSL | Official |
| 991/TCP,UDP | NAS (Netnews Administration System) | Official |
| 992/TCP,UDP | TELNET protocol over TLS/SSL | Official |
| 993/TCP | Internet Message Access Protocol over SSL (IMAPS) | Official |
| 995/TCP | Post Office Protocol 3 over TLS/SSL (POP3S) | Official |
| 999/TCP | ScimoreDB Database System | Unofficial |
| 1001/TCP | JtoMB | Unofficial |
| 1023/TCP,UDP | Reserved[1] | Official |