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Port 476 (tn-tl-fd1)

IANA assigns port 476 to tn-tl-fd1.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
tn-tl-fd1 TCP tn-tl-fd1 Ed Kress -
tn-tl-fd1 UDP tn-tl-fd1 Ed Kress -

Check what is listening on port 476

Linux: is anything listening on TCP 476?
sudo ss -tlnp 'sport = :476'
Linux: UDP 476
sudo ss -ulnp 'sport = :476'
Linux / macOS: which process owns the port
sudo lsof -nP -i :476
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':476 '
Windows (Command Prompt)
netstat -ano | findstr :476
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 476 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 476
From Windows
Test-NetConnection HOST -Port 476
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 476

Block port 476 in the firewall

ufw
sudo ufw deny 476/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 476 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 476 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 476' -Direction Inbound -Protocol TCP -LocalPort 476 -Action Block
ufw
sudo ufw deny 476/udp
iptables
sudo iptables -A INPUT -p udp --dport 476 -j DROP
nftables
sudo nft add rule inet filter input udp dport 476 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 476' -Direction Inbound -Protocol UDP -LocalPort 476 -Action Block

Related ports

474tn-tl-w1, tn-tl-w2475tcpnethaspsrv477ss7ns478spsc

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