Port 16666Vidder Tunnel Protocol

UDP port 16666 is assigned to Vidder Tunnel Protocol, a tunneling service associated with Vidder Inc.

transport: udp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as vtp

Technical Details

what runs on :16666

Vidder Tunnel Protocol is registered on port :16666 over udp to Vidder Inc, assigned October 2011. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :16666

this machine

# linux
sudo ss -ulpn 'sport = :16666'

# macos / bsd
sudo lsof -nP -i :16666

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :16666

another host

sudo nmap -sU -sV -p U:16666 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :16666

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

security averages 2.9 across 433 ports — this one sits 1.9 below.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

no security notes recorded for :16666 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :16666
service: Vidder Tunnel Protocol
transport: UDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Security Network Services
usage: IANA assigns UDP/16666 to Vidder Tunnel Protocol and lists Vidder Inc as the registrant. Public information about the protocol's deployments is sparse.
lookups: 0rank 993
added: 2026-10-17
updated: 2026-10-17
references: IANA service name registry — port 16666

Something wrong?

This record is maintained by the engineers who use port 16666. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-17.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 433 in security →

the 8 most looked-up other ports in security — 433 ports carry that label.

port	service	proto	category	risk	views
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:443	HTTPS	TCPtls	Web Services	caution	65.9k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Squid Proxy HTTP	TCP	Web Services	caution	45.8k
:8080	HTTP Alternate	TCP	Web Services	caution	44.9k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k

risk mix of the 8 listed

caution100%

2 of 8 encrypted

Port :16666Vidder Tunnel Protocol

Technical Details

Security Information

Related Ports

Port 16666Vidder Tunnel Protocol