Port directory — page 1
Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.
Common Ports Overview
FTP data transfer port for File Transfer Protocol data connections
Common Software (2)
Very Secure FTP Daemon, popular FTP server on Linux
Free FTP server software
OpenSSH listens on TCP 22 by default. Its SFTP subsystem transfers files over SSH, not the historical protocol assigned port 115.
Common Software (3)
Secure remote login and file transfer protocol
Popular SSH client on Windows platform
SSH secure shell protocol
TCP 25 carries SMTP mail transfer, commonly between mail servers. Mail clients should use the submission endpoint specified by their provider.
Common Software (4)
MailTransferProxy
MailTransferProxy
SimpleEmailTransportProtocol
Simple Mail Transfer Protocol port for mail transmission and routing services
Common Software (2)
FileTransferProtocol
FileTransferService
Time Protocol service port for network time synchronization and time queries
Common Software (2)
TimeProtocolService
RFC 868TimeProtocol
Conventional DNS uses port 53 over UDP and TCP. Treating DNS as a UDP-only service can cause incomplete or intermittent resolution.
Common Software (4)
Most widely used DNS server software
High-performance DNS server
Kubernetes cluster DNS service port
MTP ，mailtransferprotocol
Common Software (2)
mailtransferprotocolserver
mailtransfersystem
DHCPv4 servers use UDP 67 and clients use UDP 68. This is an address-lease protocol, not a website to open in a browser.
Common Software (3)
Internet Systems Consortium DHCP server
Windows built-in DHCP server
DHCPServer
DHCP client port for Dynamic Host Configuration Protocol
Common Software (3)
An HTTP URL without an explicit port normally uses 80. The actual web-server configuration determines whether and where a listener exists.
Common Software (5)
Default port for Apache HTTP server
Default port for Nginx web server
Microsoft's web server integrated in Windows Server
Kerberos authentication protocol port
Common Software (2)
MIT-developed Kerberos implementation
MicrosoftDirectoryServiceKerberosAuthentication
Post Office Protocol version 2 (POP2)
Common Software (2)
Post Office Protocol version 2 server
Legacy mail service
POP3 (Post Office Protocol 3) for receiving email
Common Software (4)
Ident - Legacy server identification system, still used by IRC servers for user authentication
Common Software (2)
Identity daemon process
IRC server authentication
IANA assigns TCP 115 to the historical Simple File Transfer Protocol. Its SFTP abbreviation must not be confused with SSH File Transfer Protocol.
Common Software (1)
IANA assigns TCP 115 to the historical Simple File Transfer Protocol. Its SFTP abbreviation must not be confused with SSH File Transfer Protocol.
SQL service port for database query and management services
Common Software (2)
OracleSQLNetworkProtocol
databaseservice
NTP (Network Time Protocol) port for time synchronization
Common Software (3)
Microsoft RPCEndpoint Mapper，forWindows RPCService
Common Software (3)
WindowsRemoteService
Distributed
MicrosoftRemoteService
IMAP on TCP 143 can upgrade a connection with STARTTLS when supported. It differs from implicit TLS on port 993.
Common Software (4)
BFTP, BackgroundFileTransferProgram
Common Software (2)
FileTransfer
TransferSystem
Simple GatewayMonitoringProtocol（[Simple Gateway Monitoring Protocol]( )，SGMP）
Common Software (2)
MonitoringProtocol
NetworkMonitoringTool
SQLservice
Common Software (2)
SQLservice
databasemanagementsystem
Distributed Mail System Protocol port for mail routing and transmission
Common Software (2)
DistributedMailServiceProtocolServer
MailSystem
SNMP (Simple Network Management Protocol) port
Common Software (3)
Open-sourceSNMP
WindowsSNMPService
Simple Network Management Protocol for network device monitoring