CyberHunter
// Other services

Port 2251: Distributed Framework Port

Port 2251 is assigned by IANA to dif-port (Distributed Framework Port).

2251

How dif-port works

Other services
client:2251dif-portresponse client:2251dif-portresponse

The client sends a request to port 2251 and the dif-port 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 2251 dangerous?

We have no specific security note for port 2251. 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 2251

ServicePortTransportDescriptionReferenceUpdated
dif-port 2251 TCP, UDP Distributed Framework Port - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2251, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2251'      # process listening on 2251
sudo lsof -nP -i :2251

macOS

sudo lsof -nP -i :2251

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2251 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2251
netstat -ano | findstr :2251

From another machine

nmap -p 2251 -sV <host>
sudo nmap -sU -p 2251 <host>
nc -zv <host> 2251

Block it in the firewall

sudo ufw deny 2251/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2251" -Direction Inbound -LocalPort 2251 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2251 used for?

Port 2251 is assigned by IANA to dif-port (Distributed Framework Port).

Is port 2251 TCP or UDP?

Port 2251 is registered for TCP and UDP.

Is it safe to open port 2251?

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 2251 is open?

On Linux run "ss -ltnup 'sport = :2251'", on macOS "lsof -nP -i :2251", and on Windows "netstat -ano | findstr :2251" to see the local process. From another machine, "nmap -p 2251 <host>" shows whether it is reachable.

05 Related