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Port 4173 (mma-discovery)

IANA assigns port 4173 to mma-discovery: MMA Device Discovery.

Registered (user) port, 1024-49151 UDP

Port 4173 is normally used over UDP; the checker tests TCP only, so a "filtered" result does not mean the UDP service is down.

IANA assignment

Service nameProtoDescriptionAssigneeReference
mma-discovery UDP MMA Device Discovery MIDI Manufacturers Assoc Inc -

Registry dates for this port: registered 2011-11-14.

Check what is listening on port 4173

Linux: UDP 4173
sudo ss -ulnp 'sport = :4173'
Linux / macOS: which process owns the port
sudo lsof -nP -i :4173
Windows (Command Prompt)
netstat -ano | findstr :4173
Windows (PowerShell)
Get-NetUDPEndpoint -LocalPort 4173

Test it from outside

UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 4173

Block port 4173 in the firewall

ufw
sudo ufw deny 4173/udp
iptables
sudo iptables -A INPUT -p udp --dport 4173 -j DROP
nftables
sudo nft add rule inet filter input udp dport 4173 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 4173' -Direction Inbound -Protocol UDP -LocalPort 4173 -Action Block

Related ports

4171ml-svnet4172pcoip4174smcluster, sm-disc4175bccp

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