IANA assigns port 1420 to timbuktu-srv4: Timbuktu Service 4 Port.
sudo ss -tlnp 'sport = :1420'sudo ss -ulnp 'sport = :1420'sudo lsof -nP -i :1420sudo netstat -tlnp | grep ':1420 'netstat -ano | findstr :1420Get-NetTCPConnection -LocalPort 1420 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 1420Test-NetConnection HOST -Port 1420nc -vzu -w 5 HOST 1420sudo ufw deny 1420/tcpsudo iptables -A INPUT -p tcp --dport 1420 -j DROPsudo nft add rule inet filter input tcp dport 1420 dropNew-NetFirewallRule -DisplayName 'Block TCP 1420' -Direction Inbound -Protocol TCP -LocalPort 1420 -Action Blocksudo ufw deny 1420/udpsudo iptables -A INPUT -p udp --dport 1420 -j DROPsudo nft add rule inet filter input udp dport 1420 dropNew-NetFirewallRule -DisplayName 'Block UDP 1420' -Direction Inbound -Protocol UDP -LocalPort 1420 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.