IANA assigns port 1259 to opennl-voice: Open Network Library Voice.
sudo ss -tlnp 'sport = :1259'sudo ss -ulnp 'sport = :1259'sudo lsof -nP -i :1259sudo netstat -tlnp | grep ':1259 'netstat -ano | findstr :1259Get-NetTCPConnection -LocalPort 1259 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 1259Test-NetConnection HOST -Port 1259nc -vzu -w 5 HOST 1259sudo ufw deny 1259/tcpsudo iptables -A INPUT -p tcp --dport 1259 -j DROPsudo nft add rule inet filter input tcp dport 1259 dropNew-NetFirewallRule -DisplayName 'Block TCP 1259' -Direction Inbound -Protocol TCP -LocalPort 1259 -Action Blocksudo ufw deny 1259/udpsudo iptables -A INPUT -p udp --dport 1259 -j DROPsudo nft add rule inet filter input udp dport 1259 dropNew-NetFirewallRule -DisplayName 'Block UDP 1259' -Direction Inbound -Protocol UDP -LocalPort 1259 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.