KnockKnock PingPort

KnockKnock opens access to your servers with one tap. It sends the knock your firewall expects, a sequence of TCP and UDP ports or ICMP echo requests of agreed sizes, and shows each step as it goes.

PORTKNOCK
• Name, host (domain, IPv4 or IPv6) and an ordered list of ports, each TCP or UDP
• Delay between ports from 0 to 1000 ms to fit your knockd timeout
• Progress for every port, and the time of the last knock in the list

PINGKNOCK
• Ordered groups of ICMP echo requests: count × data size in bytes
• The equivalent ping commands, to try the same knock from a terminal
• A table of ICMP and IP packet sizes to match your firewall rule, such as iptables -m length or MikroTik packet-size
• A warning when VPN or cellular networks may split large packets

Works with knockd and any firewall that opens access after a sequence of packets.

PRIVATE BY DESIGN
• No account, no analytics, no ads, no tracking
• Records stay on your iPhone unless you export them, and packets go straight to the hosts you enter

FREE AND PRO
The free version keeps one PortKnock server and one PingKnock target. KnockKnock Pro, a one-time purchase, removes the limit and lets you export and import your records as a file, to move them to another iPhone. No subscription.

Port knocking hides a service but does not replace SSH keys or passwords.