CyberHunter
// Other services

Port 3811: AMP

Port 3811 is assigned by IANA to amp (AMP).

3811

How amp works

Other services
client:3811ampresponse client:3811ampresponse

The client sends a request to port 3811 and the amp 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 3811 dangerous?

We have no specific security note for port 3811. 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 3811

ServicePortTransportDescriptionReferenceUpdated
amp 3811 TCP, UDP AMP - 2004-02

// source: IANA service name and port number registry

03 Check it

Which program uses port 3811, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3811'      # process listening on 3811
sudo lsof -nP -i :3811

macOS

sudo lsof -nP -i :3811

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3811 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3811
netstat -ano | findstr :3811

From another machine

nmap -p 3811 -sV <host>
sudo nmap -sU -p 3811 <host>
nc -zv <host> 3811

Block it in the firewall

sudo ufw deny 3811/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3811" -Direction Inbound -LocalPort 3811 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3811 used for?

Port 3811 is assigned by IANA to amp (AMP).

Is port 3811 TCP or UDP?

Port 3811 is registered for TCP and UDP.

Is it safe to open port 3811?

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 3811 is open?

On Linux run "ss -ltnup 'sport = :3811'", on macOS "lsof -nP -i :3811", and on Windows "netstat -ano | findstr :3811" to see the local process. From another machine, "nmap -p 3811 <host>" shows whether it is reachable.

05 Related