KnockD

Port knocking UDP Server (Supported only iptables and ipv4)

Installation

Download: Releases

Configuration

1. Edit ExecStart= in /lib/systemd/system/knockd.service file

   • Default settings: /usr/sbin/knockd --fport=47566 --sport=7566 --tcpports=21,22,25,111 --udpports=111,135,136,137,138,139 --ttl=86400 --timeout=60

   • fport: first knocking udp port

   • sport: second knocking udp port

   • tcpports: close this tcp ports

   • udpports: close this udp ports

   • ttl: time to live of access rule for ip

   • timeout: timeout beetween knocks to fport and sport

2. systemctl daemon-reload ; systemctl enable knockd

3. systemctl daemon-reload ; systemctl restart knockd

Port knocking clients

• Windows: PortQRY
• Linux: nmap -sU -p 47566,7566 1.2.3.4

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