Port 9443 (HTTPS alternate / Portainer)

Portainer's HTTPS UI (2.x), VMware vSphere services and other appliance consoles.

Registered (user) port, 1024-49151 TCP Containers and Kubernetes Expose only to trusted sources

What port 9443 is used for

Portainer's HTTPS UI (2.x), VMware vSphere services and other appliance consoles.

Security: should port 9443 be open?

Expose only to trusted sources. Portainer controls your Docker hosts; set the admin password immediately after install (it times out otherwise) and restrict access.

IANA assignment

Service nameProtoDescriptionAssigneeReference

tungsten-https TCP WSO2 Tungsten HTTPS Afkham Azeez -

tungsten-https UDP WSO2 Tungsten HTTPS Afkham Azeez -

Registry dates for this port: registered 2006-06.

Check what is listening on port 9443

Linux: is anything listening on TCP 9443?

sudo ss -tlnp 'sport = :9443'

Linux / macOS: which process owns the port

sudo lsof -nP -i :9443

Older Linux / BSD (net-tools)

sudo netstat -tlnp | grep ':9443 '

Windows (Command Prompt)

netstat -ano | findstr :9443

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 9443 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine

nc -vz -w 5 HOST 9443

From Windows

Test-NetConnection HOST -Port 9443

Allow only trusted sources on port 9443 in the firewall

Replace 203.0.113.10 with the address or network you trust. With ufw, make sure the default incoming policy is deny.

ufw (one trusted source)

sudo ufw allow from 203.0.113.10 to any port 9443 proto tcp

iptables

sudo iptables -A INPUT -p tcp --dport 9443 -s 203.0.113.10 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 9443 -j DROP

nftables

sudo nft add rule inet filter input ip saddr 203.0.113.10 tcp dport 9443 accept
sudo nft add rule inet filter input tcp dport 9443 drop

Windows Firewall

New-NetFirewallRule -DisplayName 'TCP 9443 trusted' -Direction Inbound -Protocol TCP -LocalPort 9443 -RemoteAddress 203.0.113.10 -Action Allow

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