HTTPfy

Port 4750 (ssad)

IANA assigns port 4750 to ssad: Simple Service Auto Discovery.

Registered (user) port, 1024-49151 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
ssad TCP Simple Service Auto Discovery Dr Horst Herb -
ssad UDP Simple Service Auto Discovery Dr Horst Herb -

Registry dates for this port: registered 2005-12.

Check what is listening on port 4750

Linux: is anything listening on TCP 4750?
sudo ss -tlnp 'sport = :4750'
Linux: UDP 4750
sudo ss -ulnp 'sport = :4750'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4750
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':4750 '
Windows (Command Prompt)
netstat -ano | findstr :4750
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4750 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 4750
From Windows
Test-NetConnection HOST -Port 4750
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4750

Block port 4750 in the firewall

ufw
sudo ufw deny 4750/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 4750 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 4750 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 4750' -Direction Inbound -Protocol TCP -LocalPort 4750 -Action Block
ufw
sudo ufw deny 4750/udp
iptables
sudo iptables -A INPUT -p udp --dport 4750 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4750 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4750' -Direction Inbound -Protocol UDP -LocalPort 4750 -Action Block

Related ports

4747buschtrommel4749profilemac4751spocp4752snap

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