tcping | Ping look-alike that uses TCP SYN packets | Networking library

tcping is a C library typically used in Networking applications. tcping has no bugs, it has no vulnerabilities, it has a Weak Copyleft License and it has low support. You can download it from GitHub.

Ping look-alike that uses TCP SYN packets to get around firewalls and ICMP blackholes. tcpping is a quick utility designed to emulate standard 'ping' in nearly every meaningful way and only diverge when necessary. It sends out forged TCP SYN packets and listens for a SYN/ACK or RST from the server or intermediary. It counts and reports on these results using an interface that is nearly identical to standard UNIX ping. --- Why Use Instead of Ping -------------------------------------------------. On the global Internet, some routers or systems will firewall ICMP messages while allowing TCP packets. Furthermore, some routers or hosts will 'deprioritize' ICMP ping (echo) messages destined for itself or others -- when the network gets busy, these get dropped. However, virtually all public servers and the majority of private systems have at least one TCP port open and will respond to requests on it quickly and reliably. This provides greater accuracy (or any accuracy at all) for determining if a host is available. It also yields more reliable timing for sensitive latency and loss measurements as deprioritized packets will not be a true measure of latency for normal traffic (better simulated by TCP packets). It was originally written by Steven Kehlet (blog at kehlet.cx); it was taken over, bugfixed, and now maintained (with the original author's blessing) by Jim Wyllie.