IANA assigns port 1780 to dpkeyserv.
sudo ss -tlnp 'sport = :1780'sudo ss -ulnp 'sport = :1780'sudo lsof -nP -i :1780sudo netstat -tlnp | grep ':1780 'netstat -ano | findstr :1780Get-NetTCPConnection -LocalPort 1780 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 1780Test-NetConnection HOST -Port 1780nc -vzu -w 5 HOST 1780sudo ufw deny 1780/tcpsudo iptables -A INPUT -p tcp --dport 1780 -j DROPsudo nft add rule inet filter input tcp dport 1780 dropNew-NetFirewallRule -DisplayName 'Block TCP 1780' -Direction Inbound -Protocol TCP -LocalPort 1780 -Action Blocksudo ufw deny 1780/udpsudo iptables -A INPUT -p udp --dport 1780 -j DROPsudo nft add rule inet filter input udp dport 1780 dropNew-NetFirewallRule -DisplayName 'Block UDP 1780' -Direction Inbound -Protocol UDP -LocalPort 1780 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.