MTR: Not An Ordinary Network Diagnostic Tool

MTR combines the functionality of the traceroute and ping programs in a single network diagnostic tool. And, I am certain internet service providers (ISPs) of third-world countries hate it when customers discover this tool.

I came across the tool again recently while investigating a WireGuard connection issue between an on-premises Toph server and one in Singapore.

Was it our router? Was it Linode’s infrastructure? Was it our local ISP?

A quick mtr command solved the mystery:

mtr {hostname}

Here’s what I saw when I mtr’d one of Toph’s load balancers:

You can also run mtr in report mode with the -r flag (and -c flag to set the number of pings to send).

mtr -r -c 100 {hostname}

Whatchu running at number 8, Summit IIG? Your router is leaking like a rusty bucket. 🪇