TCP/UDP Port Number Lookup

Search and inspect TCP and UDP port numbers (0 to 65535). Look up assigned services, protocols, security vulnerabilities, and firewall rules.

20TCP
FTP-DATA

File Transfer Protocol (Data Transfer)

Security Note:High (Cleartext, use SFTP)
21TCP
FTP

File Transfer Protocol (Control)

Security Note:High (Cleartext credentials)
22TCP
SSH / SFTP

Secure Shell, Secure Copy (SCP), SFTP

Security Note:Low (Encrypted, protect with SSH keys)
23TCP
Telnet

Unencrypted remote terminal protocol

Security Note:Critical (Deprecated, plaintext passwords)
25TCP
SMTP

Simple Mail Transfer Protocol (Email routing)

Security Note:Medium (Subject to spam abuse)
53TCP/UDP
DNS

Domain Name System name resolution

Security Note:Low (Susceptible to DNS amplification/spoofing)
67UDP
DHCP

Dynamic Host Configuration Protocol (Server)

Security Note:Low (Local network only)
80TCP
HTTP

Hypertext Transfer Protocol (Web traffic)

Security Note:Medium (Unencrypted, redirect to HTTPS 443)
110TCP
POP3

Post Office Protocol (Email retrieval)

Security Note:High (Cleartext, use POP3S 995)
123UDP
NTP

Network Time Protocol (Clock synchronization)

Security Note:Low
143TCP
IMAP

Internet Message Access Protocol

Security Note:High (Cleartext, use IMAPS 993)
161UDP
SNMP

Simple Network Management Protocol

Security Note:High if default public/private community strings used
389TCP/UDP
LDAP

Lightweight Directory Access Protocol

Security Note:Medium (Use LDAPS 636)
443TCP
HTTPS

HTTP over TLS/SSL (Encrypted Web Traffic)

Security Note:Low (Industry standard)
465TCP
SMTPS

Secure SMTP over SSL/TLS

Security Note:Low
587TCP
SMTP-Submission

Modern authenticated email submission

Security Note:Low
993TCP
IMAPS

IMAP over TLS/SSL (Secure Email)

Security Note:Low
995TCP
POP3S

POP3 over TLS/SSL (Secure Email)

Security Note:Low
1433TCP
MSSQL

Microsoft SQL Server Database

Security Note:High (Never expose to public internet)
1521TCP
Oracle DB

Oracle Database Listener

Security Note:High (Keep inside VPC/Private Subnet)
3000TCP
Dev Server

Common React / Node / Next.js development server

Security Note:Low (Internal testing)
3306TCP
MySQL

MySQL & MariaDB Default Database Port

Security Note:High (Restrict via Security Group)
3389TCP
RDP

Microsoft Remote Desktop Protocol

Security Note:High (Frequent target of ransomware brute-force)
5432TCP
PostgreSQL

PostgreSQL Relational Database

Security Note:High (Restrict to internal VPC CIDR)
5900TCP
VNC

Virtual Network Computing (Remote Desktop)

Security Note:High (Often lacks robust encryption)
6379TCP
Redis

Redis In-Memory Key-Value Store

Security Note:Critical (No default auth, wipe risk if exposed)
8080TCP
HTTP-Alt

Alternative HTTP port / Proxy / Tomcat / Spring

Security Note:Medium
8443TCP
HTTPS-Alt

Alternative HTTPS port / Apache Tomcat SSL

Security Note:Low
9092TCP
Kafka

Apache Kafka Distributed Message Broker

Security Note:High (Keep inside private network)
27017TCP
MongoDB

MongoDB NoSQL Document Database

Security Note:Critical (Historically attacked when left open)

Navigating Networking Architecture with Port Number Lookup

In computer networking, transport layer port numbers (0 to 65535) direct incoming network packets to specific application processes. Categorized by IANA into Well-Known Ports (0-1023), Registered Ports (1024-49151), and Dynamic/Private Ports (49152-65535), knowing standard ports is fundamental for configuring AWS Security Groups, Docker container port mappings, and reverse proxy firewalls.

Key Technical Features

Instant Search & Filter

Search by exact port integer (e.g. 5432, 6379) or service keyword (PostgreSQL, Redis, SSH, HTTP).

Protocol Specification

Identifies whether services run over TCP (connection-oriented), UDP (stateless), or both.

Security Risk Flags

Highlights insecure cleartext legacy protocols (e.g. Telnet 23, FTP 21) that should be replaced with encrypted equivalents (SSH 22, SFTP).

DevOps & Cloud Database Presets

Quick-filter presets for Databases (MySQL, Mongo, Postgres), Web Servers, Cloud VPNs, and Messaging Queues.

Docker Port Mapping Cheat Sheet

Provides instant syntax for Docker `-p <host_port>:<container_port>` configurations.

Offline-Ready Comprehensive Database

Client-side indexed database covering all major internet and cloud service ports.

Practical Engineering Scenarios

  • AWS / GCP Security Group Rules

    Safely whitelist only necessary ingress ports without accidentally exposing sensitive database ports to 0.0.0.0/0.

  • Docker Container Port Binding

    Quickly verify default internal service ports when crafting docker-compose.yml files.

  • Network Security Auditing

    Identify suspicious listening ports detected during Nmap vulnerability scanning.

  • Penetration Testing & Reconnaissance

    Correlate open ports with known service exploits and misconfigured administration panels.

Frequently Asked Questions

What is the difference between TCP and UDP ports?

TCP (Transmission Control Protocol) is connection-oriented and guarantees reliable packet delivery in order (used for HTTP, SSH, databases). UDP (User Datagram Protocol) is stateless and prioritized for speed without delivery guarantees (used for DNS, VoIP, video streaming, and online gaming).

What are the three port ranges defined by IANA?

1. Well-Known Ports (0 - 1023): Reserved for privileged system services like HTTP (80), HTTPS (443), and SSH (22). 2. Registered Ports (1024 - 49151): Assigned by IANA for specific vendor applications like PostgreSQL (5432) and Redis (6379). 3. Dynamic / Private Ports (49152 - 65535): Used for ephemeral client outbound connections.

Why should database ports never be open to the public internet?

Ports for databases like MongoDB (27017) or Redis (6379) frequently lack brute-force protection or authentication by default. Exposing them directly to the public internet allows automated ransomware bots to scan and wipe databases within hours.

What is an ephemeral port?

When your web browser connects to a remote web server on port 443, your operating system allocates a temporary random port from the dynamic range (49152-65535) to receive the return data packets.

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