How to Install and Use tcpping on Linux for Accurate TCP Latency Measurements

Why Use tcpping on Linux

Traditional ping relies on ICMP echo requests, which many firewalls block, making it useless for hosts behind restrictive firewalls. tcpping measures latency using TCP SYN packets (a half‑open connection) that are more likely to pass through such firewalls, allowing you to obtain round‑trip time (RTT) information.

Installing tcpping on Linux

tcpping

is a shell script that depends on a few utilities. Install the prerequisites first.

Install tcptraceroute

On Ubuntu/Debian: $ sudo apt-get install tcptraceroute On CentOS/RHEL:

$ sudo yum install tcptraceroute

Install bc

The GNU bc calculator is pre‑installed on most Linux distributions, but minimal environments (Docker, minimal AMIs) may lack it. Install it if needed.

On Debian/Ubuntu: $ sudo apt-get install bc On Red Hat/CentOS:

$ sudo yum install bc

Install tcpping

After the dependencies are in place, download the script from the official site, copy it to a directory in your PATH, and make it executable.

$ wget http://www.vdberg.org/~richard/tcpping
$ cp tcpping /usr/bin
$ chmod 755 tcpping

Using tcpping to Measure Latency

The basic syntax is:

tcpping [-d] [-c] [-r sec] [-x count] ipaddress [port]

-d

: prepend a timestamp to each line of output. -c: produce column‑aligned output for easier parsing. -r: set the interval between probes in seconds (default 1 s). -x: repeat the test n times (default unlimited). [port]: target port, default 80.

Root privileges are required because tcpping invokes tcptraceroute.

Example measuring RTT of a web server on port 80: tcpping www.rumenz.com Sample output shows the TCP SYN/ACK round‑trip times for each probe.

Checking Remote TCP Ports

To verify whether a remote TCP port is open, combine tcpping with nc:

$ nc -vn <ip-address> <port-number>

Additional tcpping Options

-t

: continuous ping until interrupted with Ctrl+C. -n 5: stop after 5 probes. -w 0.5: set timeout to 0.5 seconds. -d: include timestamps in each line. -s: stop automatically after a successful response. -4: force IPv4. -6: force IPv6. --file: read a list of IP/host entries from a file (one per line, optional port). tcping --file rumenz.txt These options let you tailor tcpping for various monitoring and troubleshooting scenarios.