CyberHunter
// Other services

Port 5133: Policy Commander

Port 5133 is assigned by IANA to nbt-pc (Policy Commander).

5133

How nbt-pc works

Other services
client:5133nbt-pcresponse client:5133nbt-pcresponse

The client sends a request to port 5133 and the nbt-pc 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)
01 Security

Is port 5133 dangerous?

We have no specific security note for port 5133. 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 5133

ServicePortTransportDescriptionReferenceUpdated
nbt-pc 5133 TCP, UDP Policy Commander - 2004-11

// source: IANA service name and port number registry

03 Check it

Which program uses port 5133, and is it reachable?

Linux

sudo ss -ltnup 'sport = :5133'      # process listening on 5133
sudo lsof -nP -i :5133

macOS

sudo lsof -nP -i :5133

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 5133 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 5133
netstat -ano | findstr :5133

From another machine

nmap -p 5133 -sV <host>
sudo nmap -sU -p 5133 <host>
nc -zv <host> 5133

Block it in the firewall

sudo ufw deny 5133/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 5133" -Direction Inbound -LocalPort 5133 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 5133 used for?

Port 5133 is assigned by IANA to nbt-pc (Policy Commander).

Is port 5133 TCP or UDP?

Port 5133 is registered for TCP and UDP.

Is it safe to open port 5133?

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 5133 is open?

On Linux run "ss -ltnup 'sport = :5133'", on macOS "lsof -nP -i :5133", and on Windows "netstat -ano | findstr :5133" to see the local process. From another machine, "nmap -p 5133 <host>" shows whether it is reachable.

05 Related