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Port 176 (genrad-mux)

IANA assigns port 176 to genrad-mux: GENRAD-MUX.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
genrad-mux TCP GENRAD-MUX Ron Thornton -
genrad-mux UDP GENRAD-MUX Ron Thornton -

Check what is listening on port 176

Linux: is anything listening on TCP 176?
sudo ss -tlnp 'sport = :176'
Linux: UDP 176
sudo ss -ulnp 'sport = :176'
Linux / macOS: which process owns the port
sudo lsof -nP -i :176
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':176 '
Windows (Command Prompt)
netstat -ano | findstr :176
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 176 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 176
From Windows
Test-NetConnection HOST -Port 176
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 176

Block port 176 in the firewall

ufw
sudo ufw deny 176/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 176 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 176 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 176' -Direction Inbound -Protocol TCP -LocalPort 176 -Action Block
ufw
sudo ufw deny 176/udp
iptables
sudo iptables -A INPUT -p udp --dport 176 -j DROP
nftables
sudo nft add rule inet filter input udp dport 176 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 176' -Direction Inbound -Protocol UDP -LocalPort 176 -Action Block

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