Port 16Unassigned Port
Port 16 is currently unassigned by IANA, which means it is not officially associated with a specific service or protocol. Despite this, it may occasionally be repurposed or used in unofficial or proprietary ways during internal development, experimental research, or within private networks. Administrators should be aware of its unassigned status to avoid ambiguity when monitoring network traffic or configuring firewall rules..
- transport
- tcp · udp
- in transit
- cleartext
- assignment
- unofficial
- risk
- 1/10
- lookups
- 5,796
2 transports registered
payload readable on path
used by convention
safe
rank 852 of 993 · top 86%
Technical Details
what runs on :16Port 16 is reserved as an unassigned port by the Internet Assigned Numbers Authority (IANA). No official protocol, application, or service is designated to operate specifically on this port. It remains available for experimental use or for private, non-standardized applications that do not conflict with official services.
Because it lacks an assigned protocol, network traffic on this port can vary greatly depending on user or developer intent. Developers may sometimes use unassigned ports, like port 16, during the development phase of proprietary applications or custom communication protocols. These uses should be limited to controlled environments to prevent clashes or confusion with standardized network operations.
From a standards perspective, unassigned ports like port 16 are excluded from official documentation of well-known services. Administrators should treat all traffic on this port carefully, understanding that such traffic is generally non-standard and may require additional inspection.
Security Information
exposure of :16risk score
1/ 10safe
routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.
network services averages 3.9 across 604 ports — this one sits 2.9 below.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
unofficial
used by convention, not registered — what answers here varies by deployment
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common Vulnerabilities:
- Since port 16 is unassigned, it might be targeted by attackers scanning for open unused ports that could be running obscure or unauthorized services.
- Attackers could establish backdoors or covert channels running on this port to avoid detection if network policies focus primarily on blocking known service ports.
- Unmonitored unassigned ports can sometimes be abused in misconfigured firewalls, especially if allowed universally by overly permissive rules.
Common Mitigations:
- Implement strict firewall policies to explicitly deny inbound and outbound traffic on unassigned and unused ports like port 16.
- Regularly audit network traffic to detect unexpected activity on unassigned ports, which may signify malicious use.
- Use network intrusion detection systems (IDS) to flag unexpected protocols or unusual traffic patterns occurring over this port.
- Limit experimental or proprietary service deployment on unassigned ports to controlled environments only.
Related Ports
the 8 most looked-up other ports in network services — 604 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :9080 | Groove RPC | TCPUDP | Web Services | caution | 70.8k |
| :6543 | Jetnet | UDP | Network Services | caution | 65.3k |
| :5938 | TeamViewer | TCPUDP | Remote Access | caution | 65.0k |
| :8291 | Winbox MikroTik Admin | TCP | Security | caution | 62.9k |
| :3233 | WhiskerControl Protocol | TCPUDP | Network Services | caution | 61.9k |
| :3268 | Microsoft Global Catalog (GC) | TCPUDP | Security | caution | 54.6k |
| :135 | Microsoft EPMAP | TCPUDP | Security | caution | 51.9k |
| :3128 | Tatsoft Default HTTP Proxy | TCP | Web Services | caution | 46.8k |
risk mix of the 8 listed
- caution100%
0 of 8 encrypted