CyberHunter
// Other services

Port 2904: M2UA

Port 2904 is assigned by IANA to m2ua (M2UA).

2904

How m2ua works

Other services
client:2904m2uaresponse client:2904m2uaresponse

The client sends a request to port 2904 and the m2ua service answers.

Transport
TCP · UDP · SCTP
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 2904 dangerous?

We have no specific security note for port 2904. 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 2904

ServicePortTransportDescriptionReferenceUpdated
m2ua 2904 TCP, UDP, SCTP M2UA - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2904, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2904'      # process listening on 2904
sudo lsof -nP -i :2904

macOS

sudo lsof -nP -i :2904

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2904 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2904
netstat -ano | findstr :2904

From another machine

nmap -p 2904 -sV <host>
sudo nmap -sU -p 2904 <host>
nc -zv <host> 2904

Block it in the firewall

sudo ufw deny 2904/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2904" -Direction Inbound -LocalPort 2904 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2904 used for?

Port 2904 is assigned by IANA to m2ua (M2UA).

Is port 2904 TCP or UDP?

Port 2904 is registered for TCP and UDP and SCTP.

Is it safe to open port 2904?

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 2904 is open?

On Linux run "ss -ltnup 'sport = :2904'", on macOS "lsof -nP -i :2904", and on Windows "netstat -ano | findstr :2904" to see the local process. From another machine, "nmap -p 2904 <host>" shows whether it is reachable.

05 Related