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Intermediate Estimated time: 9 min Category: Networking Published

Common Port Tables

This guide provides a complete reference of the most common TCP/UDP ports used in networking and services. It includes both IANA standard ports and widely used services.

Well-Known Ports (0-1023)

Web and HTTP Services

Port Protocol Service Description
80 TCP HTTP Hypertext Transfer Protocol
443 TCP HTTPS HTTP over TLS/SSL
8080 TCP HTTP Alt Alternative HTTP (proxies, development)
8443 TCP HTTPS Alt Alternative HTTPS

Mail Services

Port Protocol Service Description
25 TCP SMTP Simple Mail Transfer Protocol
110 TCP POP3 Post Office Protocol v3
143 TCP IMAP Internet Message Access Protocol
465 TCP SMTPS SMTP over SSL
587 TCP SMTP MSA SMTP Mail Submission Agent
993 TCP IMAPS IMAP over SSL
995 TCP POP3S POP3 over SSL

DNS and Domain Services

Port Protocol Service Description
53 TCP/UDP DNS Domain Name System
5353 UDP mDNS Multicast DNS (Bonjour)
5355 TCP LLMNR Link-Local Multicast Name Resolution

Authentication and Security Services

Port Protocol Service Description
22 TCP SSH Secure Shell
389 TCP LDAP Lightweight Directory Access Protocol
636 TCP LDAPS LDAP over SSL
1812 UDP RADIUS Remote Authentication Dial-In User Service
1813 UDP RADIUS Acct RADIUS Accounting

Database Services

Port Protocol Service Description
1433 TCP MSSQL Microsoft SQL Server
1521 TCP Oracle Oracle Database
3306 TCP MySQL MySQL Database
5432 TCP PostgreSQL PostgreSQL Database
6379 TCP Redis Redis Key-Value Store
27017 TCP MongoDB MongoDB Database

File Transfer Services

Port Protocol Service Description
20 TCP FTP Data File Transfer Protocol (data)
21 TCP FTP File Transfer Protocol (control)
69 UDP TFTP Trivial File Transfer Protocol
989 TCP FTPS Data FTP over SSL (data)
990 TCP FTPS FTP over SSL (control)

Network and System Services

Port Protocol Service Description
23 TCP Telnet Telnet (insecure)
67 UDP DHCP Server Dynamic Host Configuration Protocol
68 UDP DHCP Client DHCP Client
123 UDP NTP Network Time Protocol
161 UDP SNMP Simple Network Management Protocol
162 UDP SNMP Trap SNMP Traps

Registered Ports (1024-49151)

Web Application Services

Port Protocol Service Description
1433 TCP MSSQL Microsoft SQL Server
1521 TCP Oracle Oracle Database
2049 TCP/UDP NFS Network File System
2375 TCP Docker Docker Daemon (without TLS)
2376 TCP Docker TLS Docker Daemon with TLS
3306 TCP MySQL MySQL Database
3389 TCP RDP Remote Desktop Protocol
5432 TCP PostgreSQL PostgreSQL Database
5900 TCP VNC Virtual Network Computing
6379 TCP Redis Redis Key-Value Store
8080 TCP HTTP Alt Alternative HTTP
8443 TCP HTTPS Alt Alternative HTTPS
9000 TCP PHP-FPM PHP FastCGI Process Manager
9090 TCP Prometheus Prometheus monitoring
9200 TCP Elasticsearch Elasticsearch search engine
27017 TCP MongoDB MongoDB Database

Communication Services

Port Protocol Service Description
1194 UDP OpenVPN OpenVPN
1701 UDP L2TP Layer 2 Tunneling Protocol
1723 TCP PPTP Point-to-Point Tunneling Protocol
3478 UDP STUN Session Traversal Utilities for NAT
4500 UDP IPSec NAT-T IPsec NAT Traversal
5004 UDP RTP Real-time Transport Protocol
5005 UDP RTCP Real-time Transport Control Protocol
5060 TCP/UDP SIP Session Initiation Protocol
5061 TCP SIPS SIP over TLS

Monitoring and Management Services

Port Protocol Service Description
161 UDP SNMP Simple Network Management Protocol
162 UDP SNMP Trap SNMP Traps
199 TCP SNMP Multiplex SNMP multiplexing
10050 TCP Zabbix Agent Zabbix monitoring agent
10051 TCP Zabbix Server Zabbix server
24224 TCP Zabbix Proxy Zabbix proxy
5666 TCP NRPE Nagios Remote Plugin Executor
6556 TCP Checkmk Checkmk monitoring

Virtualization Services

Port Protocol Service Description
22 TCP SSH Secure Shell (VM access)
135 TCP RPC Microsoft RPC
139 TCP NetBIOS NetBIOS Session Service
445 TCP SMB Server Message Block
902 TCP VMware VMware Server
903 TCP VMware VMware Remote Console
2375 TCP Docker Docker Daemon
2376 TCP Docker TLS Docker Daemon with TLS
6443 TCP Kubernetes API Kubernetes API Server
10250 TCP Kubelet Kubernetes Kubelet

Dynamic/Ephemeral Ports (49152-65535)

Ranges by Operating System

System Dynamic Range Notes
Linux 32768-60999 Configurable in /proc/sys/net/ipv4/ip_local_port_range
Windows 49152-65535 Ephemeral ports
macOS 49152-65535 Ephemeral ports
IANA 49152-65535 Dynamic/Private ports

Common Services on High Ports

Port Protocol Service Description
50000-50099 TCP SAP SAP Dispatcher ports
54321 TCP PostgreSQL Alternative PostgreSQL
55000 TCP Oracle Oracle Listener
60000-61000 TCP X11 X Window System

Ports by Protocol

Specific TCP

Port Service Main Use
21 FTP File transfer
22 SSH Secure remote access
23 Telnet Remote access (insecure)
25 SMTP Mail sending
53 DNS Name resolution
80 HTTP Unencrypted web
110 POP3 Mail retrieval
143 IMAP Mail access
443 HTTPS Encrypted web
993 IMAPS Secure IMAP
995 POP3S Secure POP3

Specific UDP

Port Service Main Use
53 DNS DNS queries
67 DHCP Server IP assignment
68 DHCP Client IP request
69 TFTP Simple file transfer
123 NTP Time synchronization
161 SNMP Network monitoring
500 IPSec IPsec VPN
1194 OpenVPN OpenVPN VPN

Tools to Verify Ports

Basic Commands

# View open ports locally
netstat -tlnp
ss -tlnp

# Scan ports on a remote host
nmap -p 1-1000 example.com

# View services by port
lsof -i :80

# View port-to-service mapping
cat /etc/services | grep -E "^[0-9]"

Verification Scripts

#!/bin/bash
# Check common ports

HOST=$1
PORTS=(22 80 443 3306 5432)

echo "Checking ports on $HOST..."

for port in "${PORTS[@]}"; do
    if nc -z -w5 $HOST $port 2>/dev/null; then
        service=$(grep "^$port/" /etc/services | head -1 | awk '{print $1}')
        echo "✓ Port $port open ($service)"
    else
        echo "✗ Port $port closed"
    fi
done

Nmap for Advanced Scanning

# Quick scan of common ports
nmap --top-ports 100 example.com

# Service and version detection
nmap -sV -p 1-1000 example.com

# UDP scan
nmap -sU -p 53,67,68,123 example.com

# Firewall detection
nmap -sA example.com

Security Considerations

High-Risk Ports

  • 23 (Telnet): Cleartext transmission
  • 21 (FTP): Credentials sent in cleartext
  • 80 (HTTP): No encryption
  • 3389 (RDP): Brute-force attacks
  • 5900 (VNC): Unencrypted remote access

Best Practices

  1. Filtering: Use firewalls to limit access
  2. Monitoring: Alerts for unexpected connections
  3. Encryption: Prefer secure versions of protocols
  4. Updates: Keep services up to date
  5. Segmentation: Separate networks by function

Firewall Configuration

# UFW (Ubuntu)
ufw allow 22/tcp
ufw allow 80/tcp
ufw allow 443/tcp

# iptables
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j ACCEPT

References