No1. Most commonly used port
Port number/layer name Comment
1 tcpmux TCP port service multiplexing
5 rje Remote job entrance
7 echo Echo service
9 discard Empty service for connection testing
11 systat Used to enumerate the system status of connected ports
13 daytime Send the date and time to the requesting host
17 qotd Send daily quotes to connected hosts
18 msp message sending protocol
19 chargen Character generation service; sends an endless stream of characters
20 ftp-data FTP data port
21 ftp File Transfer Protocol (FTP) port; sometimes used by File Services Protocol (FSP)
22 ssh Secure Shell (SSH) Service
23 telnet Telnet service
25 smtp Simple Mail Transfer Protocol (SMTP)
37 time time agreement
39 rlp resource location protocol
42 nameserver Internet Name Service
43 nicname WHOIS directory service
49 tacacs Terminal access controller access control system for TCP/IP based authentication and access
50 re-mail-ck Remote Mail Checking Protocol
53 domain Domain name services (such as BIND)
63 whois++ WHOIS++, extended WHOIS service
67 bootps Bootstrap Protocol (BOOTP) service; also used by the Dynamic Host Configuration Protocol (DHCP) service
68 bootpc Bootstrap (BOOTP) client; also used by Dynamic Host Configuration Protocol (DHCP) client
69 tftp Small File Transfer Protocol (TFTP)
70 gopher Gopher Internet document search and retrieval
71 netrjs-1 Remote operation service
72 netrjs-2 Remote operation service
73 netrjs-3 Remote operation service
73 netrjs-4 Remote operation service
79 finger Finger service for user contact information
80 http Hypertext Transfer Protocol (HTTP) for World Wide Web (WWW) services
88 kerberos Kerberos network authentication system
95 supdup Telnet protocol extension
101 hostname Hostname service on SRI-NIC machine
102 iso-tsap ISO Development Environment (ISODE) Network Application
105 csnet-ns Mailbox name server; also used by CSO name servers
107 rtelnet Remote Telnet
109 pop2 Post Office Protocol Version 2
110 pop3 Post Office Protocol Version 3
111 sunrpc Remote Procedure Call (RPC) protocol for remote command execution, used by Network File System (NFS)
113 auth Authentication and Identification Protocol
115 sftp Secure File Transfer Protocol (SFTP) service
117 uucp-path Unix to Unix Copy Protocol (UUCP) path service
119 nntp Network News Transfer Protocol (NNTP) for the USENET Discussion System
123 ntp Network Time Protocol (NTP)
137 netbios-ns NETBIOS name service used by Samba in Red Hat Enterprise Linux
138 netbios-dgm NETBIOS datagram service used by Samba in Red Hat Enterprise Linux
139 netbios-ssn NET BIOS session service used by Samba in Red Hat Enterprise Linux
143 imap Internet Message Access Protocol (IMAP)
161 snmp Simple Network Management Protocol (SNMP)
162 snmptrap SNMP pitfalls
163 cmip-man Common Management Information Protocol (CMIP)
164 cmip-agent Common Management Information Protocol (CMIP)
174 mailq MAILQ
177 xdmcp X Display Manager Control Protocol
178 nextstep NeXTStep window server
179 bgp border network protocol
191 prospero Prospero Services by Cliffod Neuman
194 irc Internet Relay Chat (IRC)
199 smux SNMP UNIX multiplexing
201 at-rtmp AppleTalk routing
202 at-nbp AppleTalk name binding
204 at-echo AppleTalk echo service
206 at-zis AppleTalk block information
209 qmtp Quick Mail Transfer Protocol (QMTP)
210 z39.50 NISO Z39.50 database
213 ipx 互联网络分组交换协议（IPX），被Novell Netware环境常用的数据报协议
220 imap3 Internet Message Access Protocol version 3
245 link LINK
347 fatserv Fatmen server
363 rsvp_tunnel RSVP tunnel
369 rpc2portmap Coda file system port mapper
370 codaauth2 Coda File System Verification Service
372 ulistproc UNIX Listserv
389 ldap Lightweight Directory Access Protocol (LDAP)
427 svrloc Service Location Agreement (SLP)
434 mobileip-agent Removable Internet Protocol (IP) proxy
435 mobilip-mn Removable Internet Protocol (IP) Manager
443 https Secure Hypertext Transfer Protocol (HTTP)
444 snpp Small Network Paging Protocol
445 microsoft-ds Server Message Block (SMB) over TCP/IP
464 kpasswd Kerberos password and key replacement service
468 photuris Photuris session key management protocol
487 saft Simple Asymmetric File Transfer (SAFT) protocol
488 gss-http Generic Security Service (GSS) for HTTP
496 pim-rp-disc Rendezvous Point Discovery (RP-DISC) for Protocol Independent Multicast (PIM) Services
500 isakmp Internet Security Association and Key Management Protocol (ISAKMP)
535 iiop Internet Internal Object Request Proxy Protocol (IIOP)
538 gdomap GNUstep Distributed Object Mapper (GDOMAP)
546 dhcpv6-client Dynamic Host Configuration Protocol (DHCP) version 6 client
547 dhcpv6-server Dynamic Host Configuration Protocol (DHCP) version 6 service
554 rtsp Real-Time Streaming Protocol (RTSP)
563 nntps Network News Transfer Protocol over Secure Sockets Layer (NNTPS)
565 whoami whoami
587 submission Mail Message Submission Agent (MSA)
610 npmp-local Network Peripheral Management Protocol (NPMP) Local/Distributed Queuing System (DQS)
611 npmp-gui Network Peripheral Management Protocol (NPMP) GUI/Distributed Queuing System (DQS)
612 hmmp-ind HMMP instructions/DQS
631 ipp Internet Printing Protocol (IPP)
636 ldaps Lightweight Directory Access Protocol (LDAPS)
674 acap Application Configuration Access Protocol (ACAP)
694 ha-cluster Heartbeat service for clusters with high availability
749 kerberos-adm "kadmin" database management for Kerberos version 5 (v5)
750 kerberos-iv Kerberos version 4 (v4) service
765 webster online dictionary
767 phonebook Internet phone book
873 rsync rsync file transfer service
992 telnets Telnet over Secure Sockets Layer (TelnetS)
993 imaps Internet Message Access Protocol over Secure Sockets Layer (IMAPS)
994 ircs Internet Relay Chat over Secure Sockets Layer (IRCS)
995 pop3s Post Office Protocol Version 3 (POPS3) over Secure Sockets Layer

UNIX-specific ports (The following ports are UNIX-specific and cover services ranging from email to authentication. The name in square brackets (such as [service]) is the daemon name of the service or its common alias)
Port number/layer name Comment
512/tcp exec Used to verify remotely executed processes
512/udp biff[comsat] Asynchronous mail client (biff) and service (comsat)
513/tcp login Remote login (rlogin)
513/udp who[whod] List of logged in users
514/tcp shell[cmd] Remote shell (rshell) and remote copy (rcp) without login
514/udp syslog UNIX system log service
515 printer[spooler] printer (lpr) spool
517/udp talk Remote conversation services and clients
518/udp ntalk ntalk, remote conversation services and clients
519 utime[unixtime] UNIX Time Protocol (utime)
520/tcp efs Extended Filename Server (EFS)
520/udp router[route,routed] Routing Information Protocol (RIP)
521 ripng Routing information protocol for Internet Protocol version 6 (IPv6)
525 timed[timeserver] Time daemon (timed)
526/tcp tempo[newdate] Tempo
530/tcp courier[rpc] Courier remote procedure call (RPC) protocol
531/tcp conference[chat] internet relay chat
532 netnews Netnews
533/udp netwall Netwall for emergency broadcasts
540/tcp uucp[uucpd] Unix to Unix replication service
543/tcp klogin Kerberos version 5 (v5) remote login
544/tcp kshell Kerberos version 5 (v5) remote shell
548 afpovertcp Appletalk File Preparation Protocol (AFP) over Transmission Control Protocol (TCP)
556 remotefs[rfs_server,rfs] Brunhoff's Remote File System (RFS)

Registered ports (lists ports submitted to IANA by the networking and software communities to be officially registered in the port number list)
Port number/layer name Comment
1080 socks SOCKS web application proxy service
1236 bvcontrol[rmtcfg] Garcilis Packeten remote configuration server
1300 h323hostcallsc H.323 conference call host phone security
1433 ms-sql-s Microsoft SQL server
1434 ms-sql-m Microsoft SQL Monitor
1494 ica Citrix ICA customers
1512 wins Microsoft Windows Internet Name Server
1524 ingreslock Ingres Database Management System (DBMS) Locking Service
1525 prospero-np Unprivileged Prospero
1645 datametrics[old-radius] Datametrics/former radius project
1646 sa-msg-port[oldradacct] sa-msg-port/former radacct project
1649 kermit Kermit file transfer and management service
1701 l2tp[l2f] Layer 2 Tunneling Service (LT2P)/Layer 2 Forwarding (L2F)
1718 h323gatedisc H.323 Telecommunications Gatekeeper Discovery Mechanism
1719 h323gatestat H.323 telecommunications gatekeeper status
1720 h323hostcall H.323 Telecom host phone settings
1758 tftp-mcast Small file FTP multicast
1759 mtftp Multicast Small File FTP (MTFTP)
1789 hello Hello router communication port
1812 radius Radius dial-up authentication and accounting service
1813 radius-acct Radius Accounting
1911 mtp Starlight Network Multimedia Transfer Protocol (MTP)
1985 hsrp Cisco Hot Standby Router Protocol
1986 licensedaemon Cisco License Management Daemon
1997 gdp-port Cisco Gateway Discovery Protocol (GDP)
2049 nfs[nfsd] Network File System (NFS)
2102 zephyr-srv Zephyr notification transport and outgoing server
2103 zephyr-clt Zephyr serv-hm connection
2104 zephyr-hm Zephyr Host Manager
2401 cvspserver Concurrent Version System (CVS) client/server operation
2430/tcp venus Venus cache manager for Coda file system (codacon port)
2430/udp venus 用于Coda文件系统（callback/wbc interface界面）的Venus缓存管理器
2431/tcp venus-se Venus Transmission Control Protocol (TCP) Side Effects
2431/udp venus-se Side effects of Venus User Datagram Protocol (UDP)
2432/udp codasrv Coda file system server port
2433/tcp codasrv-se Coda File System TCP Side Effects
2433/udp codasrv-se Coda file system UDP SFTP side effects
2600 hpstgmgr[zebrasrv] HPSTGMGR; Zebra routing
2601 discp-client[zebra] discp client; Zebra integrated shell
2602 discp-server[ripd] discp server; routing information protocol daemon (ripd)
2603 servicemeter[ripngd] Service metering; RIP daemon for IPv6
2604 nsc-ccs[ospfd] NSC CCS; Open Short Path First Daemon (ospfd)
2605 nsc-posa NSC POSA; Border Network Protocol Daemon (bgpd)
2606 netmon[ospf6d] Dell Netmon; OSPF daemon for IPv6 (ospf6d)
2809 corbaloc Common Object Request Broker Architecture (CORBA) naming service locator
3130 icpv2 Internet Cache Protocol version 2 (v2); used by the Squid proxy cache server
3306 mysql MySQL database service
3346 trnsprntproxy Trnsprntproxy
4011 pxe Pre-execution environment (PXE) service
4321 rwhois Remote Whois (rwhois) service
4444 krb524 Kerberos version 5 (v5) to version 4 (v4) ticket converter
5002 rfe Radio Frequency Ethernet (RFE) Audio Broadcast System
5308 cfengine Configuration engine (Cfengine)
5999 cvsup[CVSup] CVSup file transfer and update tool
6000 x11[X] X Window System Services
7000 afs3-fileserver Andrew File System (AFS) file server
7001 afs3-callback AFS port for callbacks to the cache manager
7002 afs3-prserver AFS user and group database
7003 afs3-vlserver AFS file volume location database
7004 afs3-kaserver AFS Kerberos Authentication Service
7005 afs3-volser AFS file volume managermanagement server
7006 afs3-errors AFS Error Interpretation Service
7007 afs3-bos AFS Basic Monitoring Process
7008 afs3-update AFS server to server updater
7009 afs3-rmtsys AFS Remote Cache Manager Service
9876 sd session director
10080 amanda Advanced Maryland Automated Network Disk Archiver (Amanda) Backup Service
11371 pgpkeyserver Good Privacy (PGP)/GNU Privacy Guard (GPG) public key server
11720 h323callsigalt H.323 call signal alternation
13720 bprd Veritas NetBackup Request Daemon (bprd)
13721 bpdbm Veritas NetBackup Database Manager (bpdbm)
13722 bpjava-msvc Veritas NetBackup Java/Microsoft Visual C++ (MSVC) protocol
13724 vnetd Veritas Network Tools
13782 bpcd Vertias NetBackup
13783 vopied Veritas VOPIED protocol
22273 wnn6[wnn4] Kana/kanji conversion system
26000 quake Quake (and related) multiplayer game servers
26208 wnn6-ds
33434 traceroute Traceroute network tracking tool
Note:
/etc/services中的Comment如下：端口1236被注册为“bvcontrol”，但是它也被Gracilis Packeten远程配置服务器使用。正式name被列为主要name，未注册的name被列为别名。
Note in /etc/services: Ports 2600 to 2606 are used by the zebra package without registration. The primary name is the registered name, unregistered names used by zebra are listed as aliases.
Note in the /etc/services file: The port is registered as wnn6, but the unregistered "wnn4" is also used in the FreeWnn package.

Datagram Delivery Protocol Ports (Displays a list of ports related to the Datagram Delivery Protocol (DDP). DDP is used on AppleTalk networks)
Port number/layer 名称 Comment
1/ddp rtmp routing table management protocol
2/ddp nbp name binding protocol
4/ddp echo AppleTalk Echo protocol
6/ddp zip Block information protocol

Kerberos (Project Athena/MIT) ports (the list of ports related to the Kerberos network authentication protocol is in the marked area, v5 represents the Kerberos version 5 protocol, these ports are not registered with IANA)
Port number/layer 名称 Comment
751 kerberos_master Kerberos authentication
752 passwd_server Kerberos password (kpasswd) server
754 krb5_prop Kerberos v5 slave propagation
760 krbupdate[kreg] Kerberos registration
1109 kpop Kerberos Post Office Protocol (KPOP)
2053 knetd Kerberos demultiplexer
2105 eklogin Kerberos v5 encrypted remote login (rlogin)

Unregistered ports (these ports may be used by services or protocols installed on your Red Hat Enterprise Linux system, or they may be required for communication between Red Hat Enterprise Linux and machines running other operating systems)
Port number/layer 名称 注释
15/tcp netstat Network status (netstat)
98/tcp linuxconf Linuxconf Linux management tool
106 poppassd Post Office Protocol Password Change Daemon (POPPASSD)
465/tcp smtps Simple Mail Transfer Protocol (SMTPS) over Secure Sockets Layer
616/tcp gii Using the gateway's (routing daemon) interactive interface
808 omirr[omirrd] Online Mirror (Omirr) file mirroring service
871/tcp supfileserv Software Upgrade Protocol (SUP) Server
901/tcp swat Samba World Wide Web Administration Tool (SWAT)
953 rndc Berkeley互联网名称域版本9（BIND 9）远程名称守护进程配置工具
1127 sufiledbg Software Upgrade Protocol (SUP) Debugging
1178/tcp skkserv Simple Kana to Kanji (SKK) Japanese input server
1313/tcp xtel French Minitel text messaging system
1529/tcp support[prmsd,gnatsd] GNATS bug tracking system
2003/tcp cfinger GNU Finger service
2150 ninstall Network installation services
2988 afbackup afbackup client-server backup system
3128/tcp squid Squid web proxy cache
3455 prsvp RSVP port
5432 postgres PostgreSQL database
4557/tcp fax FAX Transmission Service (Old Service)
4559/tcp hylafax HylaFAX Client-Server Agreement (New Service)
5232 sgi-dgl SGI distributed graphics library
5354 noclog NOCOL Network Operations Center Logging Daemon (noclogd)
5355 hostmon NOCOL Network Operations Center Host Monitoring
5680/tcp canna Canna Japanese character input interface
6010/tcp x11-ssh-offset Secure Shell (SSH) X11 Forwarding Offset
6667 ircd Internet Relay Chat Daemon (ircd)
7100/tcp xfs X Font Server (XFS)
7666/tcp tircproxy Tircproxy IRC proxy service
8008 http-alt An alternative to Hypertext Transfer Protocol (HTTP)
8080 webcache World Wide Web (WWW) Caching Service
8081 tproxy transparent proxy
9100/tcp jetdirect[laserjet,hplj] Hewlett-Packard (HP)JetDirect network printing service
9359 mandelspawn[mandelbrot] Parallel Mandelbrot generator for the X Window System
10081 kamanda Amanda backup service using Kerberos
10082/tcp amandaidx Amanda backup service
10083/tcp amidxtape Amanda backup service
20011 isdnlog Integrated Services Digital Network (ISDN) login system
20012 vboxd ISDN speaker daemon (vboxd)
22305/tcp wnn4_Kr kWnn Korean input system
22289/tcp wnn4_Cn cWnn Chinese input system
22321/tcp wnn4_Tw tWnn Chinese input system (Taiwan)
24554 binkp Binkley TCP/IP Fidonet Mailer Daemon
27374 asp address search protocol
60177 tfido Ifmail FidoNet compatible mailing service
60179 fido FidoNet email and news network

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