A tool that utilizes the TCP handshake to measure latency between two hosts. Since ICMP bears both the virtues of being blocked at the firewall and bearing a lower priority in most routing engines, using standard ping techniques often times renders a less than desireable result.

This tool sends a TCP SYN packet (just the header) to a specified destination IP and port. The resulting SYN/ACK if the port of the destination host is open/listening or RST if the port and the time it takes to receive that packet is measured to yield a reasonably accurate latency measurement.

Make sure Go is installed. You can get Go for your OS of choice easily at https://golang.org.

Then:

go get github.com/sh3rp/tcping

The simplest way to execute is:

sudo tcping -h <dst ip> -p <dst port>

You can add the '-d' flag for debugging the packets sent and received.

To add the capability to tcping (and not have to run as root):

setcap cap_net_raw+ep <tcping location>