- 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.
Port 9986: KAOS secure message transport protocol for safety-critical environments
Port 9986 is assigned by IANA to kaostransport (KAOS secure message transport protocol for safety-critical environments).
9986
How kaostransport works
Other servicesThe client sends a request to port 9986 and the kaostransport service answers.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Other services
Is port 9986 dangerous?
We have no specific security note for port 9986. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 9986
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| kaostransport | 9986 | TCP | KAOS secure message transport protocol for safety-critical environments | - | 2025-10-30 |
| - | 9986 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 9986, and is it reachable?
Linux
sudo ss -ltnup 'sport = :9986' # process listening on 9986
sudo lsof -nP -i :9986macOS
sudo lsof -nP -i :9986
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 9986 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 9986 netstat -ano | findstr :9986
From another machine
nmap -p 9986 -sV <host> nc -zv <host> 9986
Block it in the firewall
sudo ufw deny 9986/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 9986" -Direction Inbound -LocalPort 9986 -Protocol TCP -Action Block # Windows
What is port 9986 used for?
Port 9986 is assigned by IANA to kaostransport (KAOS secure message transport protocol for safety-critical environments).
Is port 9986 TCP or UDP?
Port 9986 is registered for TCP.
Is it safe to open port 9986?
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 9986 is open?
On Linux run "ss -ltnup 'sport = :9986'", on macOS "lsof -nP -i :9986", and on Windows "netstat -ano | findstr :9986" to see the local process. From another machine, "nmap -p 9986 <host>" shows whether it is reachable.
Other other services ports
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp