Port 9986 (kaostransport)

IANA assigns port 9986 to kaostransport: KAOS secure message transport protocol for safety-critical environments.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference

kaostransport TCP KAOS secure message transport protocol for safety-critical environments KAOS Management Group LLC -

Registry dates for this port: registered 2025-10-30, last modified 2026-11-04.

Linux: is anything listening on TCP 9986?

sudo ss -tlnp 'sport = :9986'

Linux / macOS: which process owns the port

sudo lsof -nP -i :9986

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':9986 '

Windows (Command Prompt)

netstat -ano | findstr :9986

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 9986 -State Listen | Select LocalAddress,OwningProcess

From another machine

nc -vz -w 5 HOST 9986

From Windows

Test-NetConnection HOST -Port 9986

ufw

sudo ufw deny 9986/tcp

iptables

sudo iptables -A INPUT -p tcp --dport 9986 -j DROP

nftables

sudo nft add rule inet filter input tcp dport 9986 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'Block TCP 9986' -Direction Inbound -Protocol TCP -LocalPort 9986 -Action Block

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Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.