IANA assigns port 6055 to x11: X Window System.
sudo ss -tlnp 'sport = :6055'sudo ss -ulnp 'sport = :6055'sudo lsof -nP -i :6055sudo netstat -tlnp | grep ':6055 'netstat -ano | findstr :6055Get-NetTCPConnection -LocalPort 6055 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 6055Test-NetConnection HOST -Port 6055nc -vzu -w 5 HOST 6055sudo ufw deny 6055/tcpsudo iptables -A INPUT -p tcp --dport 6055 -j DROPsudo nft add rule inet filter input tcp dport 6055 dropNew-NetFirewallRule -DisplayName 'Block TCP 6055' -Direction Inbound -Protocol TCP -LocalPort 6055 -Action Blocksudo ufw deny 6055/udpsudo iptables -A INPUT -p udp --dport 6055 -j DROPsudo nft add rule inet filter input udp dport 6055 dropNew-NetFirewallRule -DisplayName 'Block UDP 6055' -Direction Inbound -Protocol UDP -LocalPort 6055 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.