CyberHunter
// Other services

Port 861: OWAMP-Control

Port 861 is assigned by IANA to owamp-control (OWAMP-Control), owamp-test (OWAMP-Test).

861

How owamp-control works

Other services
client:861owamp-controlresponse client:861owamp-controlresponse

The client sends a request to port 861 and the owamp-control service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned2 registered services
Range
Well-known (0-1023)
01 Security

Is port 861 dangerous?

We have no specific security note for port 861. 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 861

ServicePortTransportDescriptionReferenceUpdated
owamp-control 861 TCP OWAMP-Control RFC 4656 -
owamp-test 861 UDP OWAMP-Test RFC 8545 2018-12-21

// source: IANA service name and port number registry

03 Check it

Which program uses port 861, and is it reachable?

Linux

sudo ss -ltnup 'sport = :861'      # process listening on 861
sudo lsof -nP -i :861

macOS

sudo lsof -nP -i :861

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 861 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 861
netstat -ano | findstr :861

From another machine

nmap -p 861 -sV <host>
sudo nmap -sU -p 861 <host>
nc -zv <host> 861

Block it in the firewall

sudo ufw deny 861/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 861" -Direction Inbound -LocalPort 861 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 861 used for?

Port 861 is assigned by IANA to owamp-control (OWAMP-Control), owamp-test (OWAMP-Test).

Is port 861 TCP or UDP?

Port 861 is registered for TCP and UDP.

Is it safe to open port 861?

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 861 is open?

On Linux run "ss -ltnup 'sport = :861'", on macOS "lsof -nP -i :861", and on Windows "netstat -ano | findstr :861" to see the local process. From another machine, "nmap -p 861 <host>" shows whether it is reachable.

05 Related