IANA assigns port 1731 to msiccp: MSICCP.
sudo ss -tlnp 'sport = :1731'sudo ss -ulnp 'sport = :1731'sudo lsof -nP -i :1731sudo netstat -tlnp | grep ':1731 'netstat -ano | findstr :1731Get-NetTCPConnection -LocalPort 1731 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 1731Test-NetConnection HOST -Port 1731nc -vzu -w 5 HOST 1731sudo ufw deny 1731/tcpsudo iptables -A INPUT -p tcp --dport 1731 -j DROPsudo nft add rule inet filter input tcp dport 1731 dropNew-NetFirewallRule -DisplayName 'Block TCP 1731' -Direction Inbound -Protocol TCP -LocalPort 1731 -Action Blocksudo ufw deny 1731/udpsudo iptables -A INPUT -p udp --dport 1731 -j DROPsudo nft add rule inet filter input udp dport 1731 dropNew-NetFirewallRule -DisplayName 'Block UDP 1731' -Direction Inbound -Protocol UDP -LocalPort 1731 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.