Ports 5000–9999

Port 5000 — Development Web Server

At a Glance

• Transport: TCP

• Common service: Alternate HTTP / Dev

• Main purpose: Web development

• Status: Common convention; not an exclusive assignment

• Related ports: 80, 443, 3000, 8080

What It Does

Flask's default. Docker registries also use it. Devs test without admin privileges.

ELI Explains Another workshop: Flask picked 5000, Rails picked 3000. Build on high ports, move to 80/443 when ready.

A 10-Year-Old's Example You paint in room 5000, friend builds in 3000. Practice rooms. Art moves to gallery (80).

Remember This Common dev port — Flask and Docker registries.

Port 5060 — SIP

At a Glance

• Transport: TCP/UDP

• Common service: Session Initiation Protocol

• Main purpose: Initiates VoIP calls

• Status: Official, current

• Related ports: 5061

What It Does

VoIP call setup — inviting, codec negotiation, ringing. Voice travels separately on RTP. The signaling for modern phones.

ELI Explains Phone operator setting up calls. Connects you, rings other phone, hangs up. They don't carry your voice — just the setup.

A 10-Year-Old's Example "Switch to channel 7" on setup walkie-talkie. Both switch, talk on 7. SIP is that setup channel.

Remember This SIP initiates VoIP calls. Use SIPS (5061) for encrypted signaling.

Port 5061 — SIP over TLS

At a Glance

• Transport: TCP

• Common service: SIP over TLS

• Main purpose: Encrypted VoIP signaling

• Status: Official, current

• Related ports: 5060

What It Does

Same call setup as 5060 but encrypted. Protects who's calling whom.

ELI Explains Same operator, secret code. Still sets up your call, nobody knows who you're calling.

A 10-Year-Old's Example Setup walkie-talkie in code: "banana pineapple channel seven." Port 5061: coded channel.

Remember This Encrypted VoIP signaling. Always prefer over plaintext SIP (5060).

Port 5432 — PostgreSQL

At a Glance

• Transport: TCP

• Common service: PostgreSQL Database

• Main purpose: Database connections

• Status: Official, current

• Related ports: None

What It Does

Default PostgreSQL port. Strict standards, high reliability. Apps connect for SQL queries.

ELI Explains The meticulous librarian who double-checks everything. MySQL is friendly; PostgreSQL follows every rule.

A 10-Year-Old's Example Ultra-organized friend: Pokémon cards numbered. "Charizard?" Checks index, exact answer. PostgreSQL is that friend.

Remember This Default PostgreSQL port. Restrict and enable TLS.

Security Note Never expose directly to internet.

Port 5671 — AMQPS

At a Glance

• Transport: TCP

• Common service: AMQP over TLS

• Main purpose: Encrypted message queuing

• Status: Official, current

• Related ports: 5672

What It Does

Message queuing with TLS. RabbitMQ secure delivery between apps.

ELI Explains Armored message delivery. 5672 = postcards. 5671 = locked, tamper-proof containers.

A 10-Year-Old's Example Mail tubes: AMQP = paper. AMQPS = sealed envelope only target opens.

Remember This Encrypted message queuing. Always use over plaintext AMQP (5672).

Port 5672 — AMQP

At a Glance

• Transport: TCP

• Common service: Advanced Message Queuing Protocol

• Main purpose: Message routing between apps

• Status: Official, current

• Related ports: 5671

What It Does

Routes messages through exchanges and queues. RabbitMQ's protocol. Decouples services.

ELI Explains Post office with sorting rules. Drop in "orders" — no address needed. Delivers to subscribers.

A 10-Year-Old's Example Teacher's trays: "Homework," "Permission Slips." Drop in right tray. Processed in order.

Remember This AMQP routes messages between apps. Use AMQPS (5671) for encryption.

Port 5900 — VNC

At a Glance

• Transport: TCP

• Common service: Virtual Network Computing

• Main purpose: Graphical remote desktop

• Status: Official, current

• Related ports: None

What It Does

Provides graphical remote desktop access using the Remote Framebuffer protocol. Security features vary by VNC implementation; protect the service with strong authentication, a secure implementation, or a VPN or SSH tunnel.

ELI Explains Webcam on a screen with remote keyboard. You see and control from afar. Always use a secure tunnel.

A 10-Year-Old's Example Camera on homework, remote pen. From friend's house, watch feed and write. VNC is that setup. Use a lock.

Remember This VNC provides graphical remote access. Verify the implementation's security and protect it with a VPN or SSH tunnel when needed.

Port 5985 — WinRM HTTP

At a Glance

• Transport: TCP

• Common service: Windows Remote Management (HTTP)

• Main purpose: PowerShell Remoting over HTTP

• Status: Official, current

• Related ports: 5986

What It Does

Carries WS-Management and PowerShell remoting over HTTP. With Kerberos, NTLM, or Negotiate, WinRM can provide message-level encryption even though the transport is HTTP. HTTPS on port 5986 additionally provides TLS transport and certificate-based server identity.

ELI Explains Two protected delivery choices: port 5985 can seal each message after authentication, while port 5986 also places the entire conversation inside a TLS-protected tunnel.

A 10-Year-Old's Example A robot can receive sealed instruction cards over port 5985. Port 5986 adds a locked delivery tube whose certificate helps identify the correct robot.

Remember This WinRM uses HTTP on port 5985. Message encryption depends on authentication; HTTPS on port 5986 adds TLS transport protection.

Port 5986 — WinRM HTTPS

At a Glance

• Transport: TCP

• Common service: Windows Remote Management (HTTPS)

• Main purpose: Encrypted PowerShell Remoting

• Status: Official, current

• Related ports: 5985

What It Does

Carries WS-Management and PowerShell remoting over HTTPS. TLS protects the transport and can provide certificate-based server identity in addition to WinRM's authentication protections.

ELI Explains The same remote-management conversation carried through a TLS-protected channel. The certificate also helps the client confirm which server answered.

A 10-Year-Old's Example Chore robot with spy earpiece. Whisper "vacuum" — only robot hears. Port 5986 is that earpiece.

Remember This WinRM HTTPS adds TLS transport protection on port 5986; use it when certificate-based transport security is required.

Port 6379 — Redis

At a Glance

• Transport: TCP

• Common service: Redis Data Store

• Main purpose: In-memory caching

• Status: Official, current

• Related ports: None

What It Does

In-memory data store for caching and sessions. Sub-millisecond responses. Alongside databases.

ELI Explains Notepad on desk vs. basement filing cabinet. Only frequently-used stuff, instant grab. Super-fast short-term memory.

A 10-Year-Old's Example Five crayons in pencil case — grab red instantly. Rest in closet box. Redis is that pencil case.

Remember This Redis: lightning-fast caching. Set a password, restrict access.

Security Note Configure Redis ACLs or authentication, bind only to intended interfaces, keep protected mode enabled, and restrict network access.

Port 8080 — HTTP Alternate

At a Glance

• Transport: TCP

• Common service: HTTP Alternate / Proxy

• Main purpose: Secondary web server / proxy

• Status: Official, current

• Related ports: 80, 443, 8443

What It Does

Most recognized alternate HTTP. Tomcat, Jenkins, proxies default here. Universal web app port.

ELI Explains Universal backup door for web servers. 80 = front door; 8080 = side door everyone knows.

A 10-Year-Old's Example Cafeteria main entrance (80). Door 8080 = kitchen staff entrance everyone recognizes.

Remember This Port 8080 is the most common HTTP alternate — app servers, proxies, dev tools.

Port 8443 — HTTPS Alternate

At a Glance

• Transport: TCP

• Common service: HTTPS Alternate

• Main purpose: Secondary encrypted web server

• Status: Common convention; not an exclusive assignment

• Related ports: 443, 8080

What It Does

A common convention for alternate HTTPS endpoints, including application servers and administrative interfaces. It is not an exclusive generic HTTPS assignment, so verify the actual service.

ELI Explains Secure side door. 8080's encrypted partner. Same as 443:80 relationship. :8443 = encrypted web.

A 10-Year-Old's Example Main secure entrance (443) + secondary (8443) for staff. Same security, less crowded.

Remember This Port 8443 is commonly used for alternate HTTPS, but the actual service must be verified.

Port 8883 — MQTT over TLS

At a Glance

• Transport: TCP

• Common service: MQTT over TLS

• Main purpose: Encrypted IoT messaging

• Status: Official, current

• Related ports: 1883

What It Does

MQTT + TLS. IoT messaging with encryption for sensor data and device commands.

ELI Explains IoT bulletin board in a locked room. Same notes — temps, alerts — but key required.

A 10-Year-Old's Example Open bulletin board to locked cabinet. Same notes, combination required. Port 8883 is that cabinet.

Remember This Encrypted MQTT. Always prefer over plaintext (1883).

Port 9200 — Elasticsearch HTTP

At a Glance

• Transport: TCP

• Common service: Elasticsearch REST API

• Main purpose: Search and analytics API

• Status: Common convention; not an exclusive assignment

• Related ports: 9300

What It Does

HTTP API for indexing and searching data. Fastest librarian you'll meet.

ELI Explains Hand them a doc — milliseconds later, findable. "Every doc about volcanoes after 2020" — scans millions instantly.

A 10-Year-Old's Example Magic notebook: "find dinosaur pages" — those pages glow. Port 9200 is that magic.

Remember This Elasticsearch API. Enable auth, restrict network access.

Security Note Enable authentication and restrict to trusted networks.