Networking

Common Network Ports: TCP and UDP Reference List

meine-ip.info Editorial · · 3 min read · Updated May 2026
ports TCP UDP firewall networking reference
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Common network ports at a glance

The most-used Well-Known ports (0–1023) and selected Registered ports (1024–49151), with service, transport, encryption status and a brief note. To check whether a specific port is open on a host, use the Port Scanner.

System / Remote access

Port Proto Service Encrypted Note
22 TCP SSH Linux remote login, SCP, SFTP
23 TCP Telnet Clear-text — should be disabled
3389 TCP/UDP RDP Windows Remote Desktop
5900 TCP VNC Often tunneled over SSH
5985/5986 TCP WinRM (HTTP/HTTPS) ⚠/✅ PowerShell remoting

Web & APIs

Port Proto Service Encrypted Note
80 TCP HTTP Should redirect to HTTPS
443 TCP/UDP HTTPS / HTTP/3 (QUIC) UDP/443 for HTTP/3
8080 TCP HTTP alt Proxies, dev servers
8443 TCP HTTPS alt Admin panels
3000 TCP Node.js, Grafana Dev default
5000 TCP Flask, various Dev default

Email

Port Proto Service Encrypted Note
25 TCP SMTP (MX relay) STARTTLS Server-to-server mail
587 TCP SMTP Submission STARTTLS Client → server (must auth)
465 TCP SMTPS ✅ (implicit TLS) Alternative to 587
110 TCP POP3 STARTTLS Legacy
995 TCP POP3S
143 TCP IMAP STARTTLS
993 TCP IMAPS Recommended

File transfer

Port Proto Service Encrypted Note
20/21 TCP FTP (data/control) Legacy; prefer SFTP (22) or FTPS
22 TCP SFTP SSH subsystem
990 TCP FTPS (implicit)
989 TCP FTPS data
445 TCP SMB SMB 3.0+ encrypts; disable SMBv1
2049 TCP/UDP NFS Use Krb5 for auth

Databases

Port Proto Service Encrypted Note
1433 TCP MS SQL Server TLS optional
3306 TCP MySQL / MariaDB TLS recommended
5432 TCP PostgreSQL ssl=on
6379 TCP Redis Auth + TLS required
27017 TCP MongoDB TLS recommended
9200/9300 TCP Elasticsearch Never expose to internet

DNS / DHCP / Directory

Port Proto Service Encrypted Note
53 TCP/UDP DNS UDP < 512 bytes, otherwise TCP
853 TCP/UDP DNS over TLS / QUIC DoT / DoQ
443 TCP DNS over HTTPS (DoH) Browser default resolver
67/68 UDP DHCP (server/client)
389 TCP LDAP STARTTLS
636 TCP LDAPS
88 TCP/UDP Kerberos ✅ (internal)

Realtime / Messaging / Gaming

Port Proto Service Note
5060 TCP/UDP SIP VoIP signalling
5061 TCP SIPS TLS SIP
5222 TCP XMPP-Client Jabber, Matrix bridges
5269 TCP XMPP-Server
1883 TCP MQTT IoT broker
8883 TCP MQTT-TLS
6667 TCP IRC
25565 TCP Minecraft
27015 UDP Source games CS, TF2, Garry's Mod
3478 UDP STUN WebRTC

Tunnels / VPN

Port Proto Service Note
1194 UDP OpenVPN Default
51820 UDP WireGuard Default
500 UDP IKE (IPsec)
4500 UDP IPsec NAT-T
1701 UDP L2TP
1723 TCP PPTP Insecure, avoid

Monitoring / Management

Port Proto Service Note
161/162 UDP SNMP / Trap Avoid public community
9090 TCP Prometheus
3000 TCP Grafana
9100 TCP Node Exporter
5601 TCP Kibana

Well-Known / Registered / Dynamic — what's the difference?

Range Numbers Assignment
Well-Known 0 – 1023 IANA reserved (root-only on Linux)
Registered 1024 – 49151 IANA-registered for applications
Dynamic / Ephemeral 49152 – 65535 Allocated temporarily by clients

Security rules of thumb

  1. Never expose clear-text protocols (Telnet, FTP, HTTP, POP3, IMAP, SNMPv2) to the open internet.
  2. Database ports (1433, 3306, 5432, 6379, 27017, 9200) belong behind a firewall/VPN — they are constantly scanned.
  3. Disable SMBv1 (445/TCP) — vulnerable to WannaCry et al.
  4. PPTP (1723) is broken — replace with WireGuard or OpenVPN.
  5. SSH (22): key-only auth, fail2ban, port-knocking or moving to a higher port reduce bot traffic.

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