HTTPfy

Port 471 (mondex)

IANA assigns port 471 to mondex: Mondex.

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

IANA assignment

Service nameProtoDescriptionAssigneeReference
mondex TCP Mondex Bill Reding -
mondex UDP Mondex Bill Reding -

Check what is listening on port 471

Linux: is anything listening on TCP 471?
sudo ss -tlnp 'sport = :471'
Linux: UDP 471
sudo ss -ulnp 'sport = :471'
Linux / macOS: which process owns the port
sudo lsof -nP -i :471
Older Linux / BSD (net-tools)
sudo netstat -tlnp | grep ':471 '
Windows (Command Prompt)
netstat -ano | findstr :471
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 471 -State Listen | Select LocalAddress,OwningProcess

Test it from outside

From another machine
nc -vz -w 5 HOST 471
From Windows
Test-NetConnection HOST -Port 471
UDP probe (no reply does not prove it is closed)
nc -vzu -w 5 HOST 471

Block port 471 in the firewall

ufw
sudo ufw deny 471/tcp
iptables
sudo iptables -A INPUT -p tcp --dport 471 -j DROP
nftables
sudo nft add rule inet filter input tcp dport 471 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block TCP 471' -Direction Inbound -Protocol TCP -LocalPort 471 -Action Block
ufw
sudo ufw deny 471/udp
iptables
sudo iptables -A INPUT -p udp --dport 471 -j DROP
nftables
sudo nft add rule inet filter input udp dport 471 drop
Windows Firewall
New-NetFirewallRule -DisplayName 'Block UDP 471' -Direction Inbound -Protocol UDP -LocalPort 471 -Action Block

Related ports

469rcp470scx-proxy472ljk-login473hybrid-pop

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