IANA assigns port 3401 to filecast.
sudo ss -tlnp 'sport = :3401'sudo ss -ulnp 'sport = :3401'sudo lsof -nP -i :3401sudo netstat -tlnp | grep ':3401 'netstat -ano | findstr :3401Get-NetTCPConnection -LocalPort 3401 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 3401Test-NetConnection HOST -Port 3401nc -vzu -w 5 HOST 3401sudo ufw deny 3401/tcpsudo iptables -A INPUT -p tcp --dport 3401 -j DROPsudo nft add rule inet filter input tcp dport 3401 dropNew-NetFirewallRule -DisplayName 'Block TCP 3401' -Direction Inbound -Protocol TCP -LocalPort 3401 -Action Blocksudo ufw deny 3401/udpsudo iptables -A INPUT -p udp --dport 3401 -j DROPsudo nft add rule inet filter input udp dport 3401 dropNew-NetFirewallRule -DisplayName 'Block UDP 3401' -Direction Inbound -Protocol UDP -LocalPort 3401 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.