CyberHunter
Local dataset, no network
// Other services

Port 4066: Performance Measurement and Analysis

Port 4066 is assigned by IANA to pmas (Performance Measurement and Analysis).

4066

How pmas works

Other services
client:4066pmasresponse client:4066pmasresponse

The client sends a request to port 4066 and the pmas service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
Category
Other services
01 Security

Is port 4066 dangerous?

We have no specific security note for port 4066. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 4066

ServicePortTransportDescriptionReferenceUpdated
pmas 4066 TCP, UDP Performance Measurement and Analysis - 2007-02

// source: IANA service name and port number registry

03 Check it

Which program uses port 4066, and is it reachable?

Linux

sudo ss -ltnup 'sport = :4066'      # process listening on 4066
sudo lsof -nP -i :4066

macOS

sudo lsof -nP -i :4066

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4066 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 4066
netstat -ano | findstr :4066

From another machine

nmap -p 4066 -sV <host>
sudo nmap -sU -p 4066 <host>
nc -zv <host> 4066

Block it in the firewall

sudo ufw deny 4066/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 4066" -Direction Inbound -LocalPort 4066 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 4066 used for?

Port 4066 is assigned by IANA to pmas (Performance Measurement and Analysis).

Is port 4066 TCP or UDP?

Port 4066 is registered for TCP and UDP.

Is it safe to open port 4066?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.

How do I check if port 4066 is open?

On Linux run "ss -ltnup 'sport = :4066'", on macOS "lsof -nP -i :4066", and on Windows "netstat -ano | findstr :4066" to see the local process. From another machine, "nmap -p 4066 <host>" shows whether it is reachable.

05 Related
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp

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