Port Reference Guide
Complete reference guide for common network ports and services
Calculator
Educational Reference Only
Browsers cannot scan ports directly due to security restrictions. This is a comprehensive reference guide for understanding common network ports. For actual port scanning, use dedicated tools like Nmap on your own systems with proper authorization.
Port Scanning Legality
Port scanning without authorization may be illegal in your jurisdiction. Always ensure you have explicit written permission before scanning any network or system you do not own. Unauthorized scanning can result in criminal charges and civil liability.
Web Services
HTTP, HTTPS, and web-related protocols
HTTP
TCPHypertext Transfer Protocol - Standard web traffic (unencrypted)
HTTPS
TCPHTTP Secure - Encrypted web traffic using TLS/SSL
HTTP Alternate
TCPAlternative HTTP port, commonly used for proxies and development
HTTPS Alternate
TCPAlternative HTTPS port for secure web services
Dev Server
TCPCommon development server port (Node.js, React, etc.)
Dev Server
TCPFlask, Python development servers, Docker Registry
HTTP Alternate
TCPAlternative HTTP port for development and applications
PHP-FPM / SonarQube
TCPPHP FastCGI Process Manager, SonarQube, various apps
Email Services
SMTP, POP3, IMAP email protocols
SMTP
TCPSimple Mail Transfer Protocol - Email transmission between servers
SMTPS
TCPSMTP over SSL - Encrypted email submission
SMTP Submission
TCPEmail submission port with STARTTLS encryption
POP3
TCPPost Office Protocol v3 - Email retrieval (unencrypted)
POP3S
TCPPOP3 over SSL - Secure email retrieval
IMAP
TCPInternet Message Access Protocol - Email access (unencrypted)
IMAPS
TCPIMAP over SSL - Secure email access
Database Services
MySQL, PostgreSQL, MongoDB, Redis, and other databases
MySQL
TCPMySQL/MariaDB database server
PostgreSQL
TCPPostgreSQL database server
MongoDB
TCPMongoDB NoSQL database server
Redis
TCPRedis in-memory data store
Memcached
TCP/UDPMemcached distributed caching system
MSSQL
TCPMicrosoft SQL Server database
Oracle DB
TCPOracle database listener
Elasticsearch
TCPElasticsearch REST API
Cassandra
TCPApache Cassandra CQL native protocol
CouchDB
TCPApache CouchDB REST API
Security & Remote Access
SSH, VPN, and secure access protocols
SSH
TCPSecure Shell - Encrypted remote access and file transfer
Telnet
TCPUnencrypted remote access (INSECURE)
RDP
TCPRemote Desktop Protocol - Windows remote access
VNC
TCPVirtual Network Computing - Remote desktop
OpenVPN
UDPOpenVPN tunnel - Secure VPN connections
IKE/IPSec
UDPInternet Key Exchange for IPSec VPN
IPSec NAT-T
UDPIPSec NAT Traversal
WireGuard
UDPWireGuard VPN - Modern, fast VPN protocol
File Transfer
FTP, SFTP, and file sharing protocols
FTP Data
TCPFTP data transfer (active mode)
FTP Control
TCPFTP command/control channel
TFTP
UDPTrivial File Transfer Protocol - Simple file transfer
SFTP (legacy)
TCPSimple File Transfer Protocol (not SSH FTP)
FTPS
TCPFTP over TLS/SSL (implicit)
SMB
TCPServer Message Block - Windows file sharing
NetBIOS Name
UDPNetBIOS Name Service
NetBIOS Session
TCPNetBIOS Session Service - Legacy file sharing
NFS
TCP/UDPNetwork File System - Unix/Linux file sharing
Network Infrastructure
DNS, DHCP, NTP, and network management
DNS
TCP/UDPDomain Name System - Domain name resolution
DHCP Server
UDPDynamic Host Configuration Protocol - Server
DHCP Client
UDPDHCP Client - Receives IP configuration
NTP
UDPNetwork Time Protocol - Time synchronization
SNMP
UDPSimple Network Management Protocol
SNMP Trap
UDPSNMP Trap - Unsolicited notifications
BGP
TCPBorder Gateway Protocol - Internet routing
Syslog
UDPSystem logging protocol
LDAP
TCPLightweight Directory Access Protocol
LDAPS
TCPLDAP over SSL/TLS
Messaging & Queues
Message brokers and communication services
AMQP
TCPAdvanced Message Queuing Protocol (RabbitMQ)
AMQPS
TCPAMQP over TLS
Kafka
TCPApache Kafka broker
MQTT
TCPMessage Queuing Telemetry Transport
MQTTS
TCPMQTT over TLS
ActiveMQ
TCPApache ActiveMQ OpenWire protocol
Containers & Orchestration
Docker, Kubernetes, and container platforms
Docker (Unencrypted)
TCPDocker daemon API (INSECURE)
Docker (TLS)
TCPDocker daemon API with TLS
etcd Client
TCPetcd client API (Kubernetes)
etcd Peer
TCPetcd peer communication
Kubernetes API
TCPKubernetes API Server
Kubelet
TCPKubernetes Kubelet API
Kubelet Read-Only
TCPKubelet read-only API (deprecated)
Flannel VXLAN
UDPFlannel overlay network
Port Reference Guide
This reference includes 66 commonly used network ports across 8 categories. Click on any port to expand and see detailed security recommendations, common usage scenarios, and protocol information. Use this guide to understand what services run on different ports and how to secure them.
How to Use
Scan for open ports on a server or IP address
Enter target
Type the IP address or hostname to scan
Select ports
Choose common ports, custom port range, or specific ports to scan
Review results
See which ports are open, closed, or filtered and their associated services
Frequently Asked Questions
A port scanner checks which network ports are open on a server or device. Open ports indicate running services (e.g., port 80 for HTTP, 443 for HTTPS, 22 for SSH). This helps identify available services, potential security vulnerabilities, and network configuration issues.
Common ports include: 21 (FTP), 22 (SSH), 23 (Telnet), 25 (SMTP), 53 (DNS), 80 (HTTP), 110 (POP3), 143 (IMAP), 443 (HTTPS), 993 (IMAP SSL), 995 (POP3 SSL), 3306 (MySQL), 3389 (RDP), and 5432 (PostgreSQL).
Scanning your own systems and networks is legal. Scanning other systems without permission may violate computer misuse laws in many jurisdictions. Always ensure you have authorization before scanning any systems you do not own or manage.
Open ports expose services that attackers may exploit through known vulnerabilities, brute force attacks, or misconfigurations. Unnecessary open ports increase attack surface. Regular port scanning helps identify and close unneeded services to improve security.
Network & Security
IP lookup, DNS tools, SSL checker and security utilities