HTTPfy

Port 4311 (p6ssmc)

IANA assigns port 4311 to p6ssmc: P6R Secure Server Management Console.

Registered (user) port, 1024-49151 TCP

IANA assignment

Service nameProtoDescriptionAssigneeReference
p6ssmc TCP P6R Secure Server Management Console Jim Susoy -

Registry dates for this port: registered 2010-01-21.

Check what is listening on port 4311

Linux: is anything listening on TCP 4311?
sudo ss -tlnp 'sport = :4311'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4311
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4311 '
Windows (Command Prompt)
netstat -ano | findstr :4311
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4311 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4311
From Windows
Test-NetConnection HOST -Port 4311

Block port 4311 in the firewall

ufw
sudo ufw deny 4311/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4311 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4311 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4311' -Direction Inbound -Protocol TCP -LocalPort 4311 -Action Block

Related ports

All port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.