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Port 478 (spsc)

IANA assigns port 478 to spsc.

Well-known (system) port, 0-1023 TCPUDP

IANA assignment

Service nameProtoDescriptionAssigneeReference
spsc TCP spsc Mike Rieker -
spsc UDP spsc Mike Rieker -

Check what is listening on port 478

Linux: is anything listening on TCP 478?
sudo ss -tlnp 'sport = :478'
Linux: UDP 478
sudo ss -ulnp 'sport = :478'
Linux / macOS: which process owns the port
sudo lsof -nP -i :478
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':478 '
Windows (Command Prompt)
netstat -ano | findstr :478
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 478 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 478
From Windows
Test-NetConnection HOST -Port 478
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 478

Block port 478 in the firewall

ufw
sudo ufw deny 478/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 478 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 478 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 478' -Direction Inbound -Protocol TCP -LocalPort 478 -Action Block
ufw
sudo ufw deny 478/udp
iptables
sudo iptables -A INPUT -p udp --dport 478 -j DROP
nftables
sudo nft add rule inet filter input udp dport 478 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 478' -Direction Inbound -Protocol UDP -LocalPort 478 -Action Block

Related ports

476tn-tl-fd1477ss7ns479iafserver480iafdbase

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