Reference Database
This tool provides information about common network ports and their services. To scan for open ports on a system, use tools like nmap, netstat, or specialized network scanners.
Showing 5986 of 5986 ports
| Port | Protocol | Service | Description | Category | Security |
|---|---|---|---|---|---|
| 1 | Both | tcpmux | Multiplexer | Other | Configure firewall rules and authentication appropriately. |
| 5 | Both | rje | Entry | Other | Configure firewall rules and authentication appropriately. |
| 7 | Both | echo | Echo | Network | Configure firewall rules and authentication appropriately. |
| 9 | Both | discard | Discard | Network | Configure firewall rules and authentication appropriately. |
| 11 | Both | systat | Users | Other | Configure firewall rules and authentication appropriately. |
| 13 | Both | daytime | Daytime | Network | Configure firewall rules and authentication appropriately. |
| 17 | Both | qotd | Day | Network | Configure firewall rules and authentication appropriately. |
| 18 | Both | msp | (historic) | Other | Configure firewall rules and authentication appropriately. |
| 19 | Both | chargen | Generator | Network | Configure firewall rules and authentication appropriately. |
| 20 | Both | ftp-data | Data] | File Transfer | Configure firewall rules and authentication appropriately. |
| 21 | Both | ftp | [Control] | File Transfer | 🟡 Unencrypted. Use encrypted alternative or VPN. Restrict network access. |
| 22 | Both | ssh | Protocol | File Transfer | 🟢 Encrypted protocol. Ensure strong cipher suites and valid certificates. |
| 23 | Both | telnet | Telnet | Remote Access | 🔴 Critical risk. Frequently exploited. Never expose to internet. |
| 25 | Both | smtp | Transfer | 🟡 Unencrypted. Use encrypted alternative or VPN. Restrict network access. | |
| 27 | Both | nsw-fe | FE | Other | Configure firewall rules and authentication appropriately. |
| 29 | Both | msg-icp | ICP | Other | Configure firewall rules and authentication appropriately. |
| 31 | Both | msg-auth | Authentication | Other | Configure firewall rules and authentication appropriately. |
| 33 | Both | dsp | Protocol | Other | Configure firewall rules and authentication appropriately. |
| 37 | Both | time | Time | Time | Configure firewall rules and authentication appropriately. |
| 38 | Both | rap | Protocol | Other | Configure firewall rules and authentication appropriately. |
| 39 | Both | rlp | Protocol | Other | Configure firewall rules and authentication appropriately. |
| 41 | Both | graphics | Graphics | Other | Configure firewall rules and authentication appropriately. |
| 42 | Both | name | Server | Other | Configure firewall rules and authentication appropriately. |
| 43 | Both | nicname | Is | Other | Configure firewall rules and authentication appropriately. |
| 44 | Both | mpm-flags | Protocol | Other | Configure firewall rules and authentication appropriately. |
| 45 | Both | mpm | [recv] | Other | Configure firewall rules and authentication appropriately. |
| 46 | Both | mpm-snd | send] | Other | Configure firewall rules and authentication appropriately. |
| 48 | Both | auditd | Daemon | Other | Configure firewall rules and authentication appropriately. |
| 49 | Both | tacacs | (TACACS) | Other | Configure firewall rules and authentication appropriately. |
| 50 | Both | re-mail-ck | Protocol | Configure firewall rules and authentication appropriately. | |
| 52 | Both | xns-time | Protocol | Time | Configure firewall rules and authentication appropriately. |
| 53 | Both | domain | Server | DNS | Configure firewall rules and authentication appropriately. |
| 54 | Both | xns-ch | Clearinghouse | Other | Configure firewall rules and authentication appropriately. |
| 55 | Both | isi-gl | Language | Other | Configure firewall rules and authentication appropriately. |
| 56 | Both | xns-auth | Authentication | Other | Configure firewall rules and authentication appropriately. |
| 58 | Both | xns-mail | Mail | Configure firewall rules and authentication appropriately. | |
| 62 | Both | acas | Services | Other | Configure firewall rules and authentication appropriately. |
| 63 | Both | whoispp | whois++ | Other | Configure firewall rules and authentication appropriately. |
| 64 | Both | covia | (CI) | Other | Configure firewall rules and authentication appropriately. |
| 65 | Both | tacacs-ds | Service | Other | Configure firewall rules and authentication appropriately. |
| 66 | Both | sql-net | SQL*NET | Database | Configure firewall rules and authentication appropriately. |
| 67 | Both | bootps | Server | Network | Configure firewall rules and authentication appropriately. |
| 68 | Both | bootpc | Client | Network | Configure firewall rules and authentication appropriately. |
| 69 | Both | tftp | Transfer | File Transfer | 🟡 Unencrypted. Use encrypted alternative or VPN. Restrict network access. |
| 70 | Both | gopher | Gopher | Other | Configure firewall rules and authentication appropriately. |
| 71 | Both | netrjs-1 | Service | Other | Configure firewall rules and authentication appropriately. |
| 72 | Both | netrjs-2 | Service | Other | Configure firewall rules and authentication appropriately. |
| 73 | Both | netrjs-3 | Service | Other | Configure firewall rules and authentication appropriately. |
| 74 | Both | netrjs-4 | Service | Other | Configure firewall rules and authentication appropriately. |
| 76 | Both | deos | Store | Other | Configure firewall rules and authentication appropriately. |
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Security Indicator Legend
Green: Secure/Encrypted
Yellow: Conditional Security
Red: Critical/Dangerous
Gray: Unknown/Not in DB
Common Port Groups
Security Best Practices
- •Never expose database ports (3306, 5432, 1433, 27017, 6379) to the internet. Use SSH tunnels or VPNs.
- •Disable legacy protocols like Telnet (23), FTP (21), and HTTP (80) in favor of encrypted alternatives.
- •Use firewalls to restrict access to only necessary ports and trusted IP addresses.
- •Enable authentication on all services, especially those that default to no auth (Redis, Memcached, MongoDB).
- •Regularly audit open ports using tools like nmap, netstat, or ss to identify unexpected services.
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References & Citations
- Internet Assigned Numbers Authority. (2024). IANA Port Number Registry. Retrieved from https://www.iana.org/assignments/service-names-port-numbers/ (accessed January 2025)
- Gordon "Fyodor" Lyon. (2009). Nmap Network Scanning Guide. Retrieved from https://nmap.org/book/ (accessed January 2025)
Note: These citations are provided for informational and educational purposes. Always verify information with the original sources and consult with qualified professionals for specific advice related to your situation.
Key Security Terms
Understand the essential concepts behind this tool
MAC Address
A unique hardware identifier assigned to network interfaces for local network communication.
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Port Numbers
Numerical identifiers (0-65535) used to route network traffic to specific services on a device.
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Subnet Mask
A 32-bit number that divides an IP address into network and host portions for routing.
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Penetration Testing
Authorized simulated cyberattacks against systems to identify security vulnerabilities before malicious actors exploit them.
Learn more →