Trace (traceroute)

What it does: maps the route to a destination hop by hop using increasing TTL. Has the same IPv4/IPv6/Auto family picker as Ping — useful when a path works over one family but not the other (some ISPs tunnel IPv6, which can make plain IPv4 traceroutes to the open internet fail even though the connection itself is fine).

Safe to run: yes.

Reading results: each line is a router on the path. A row of * means that hop didn't reply (often normal — many routers de-prioritize it). Where replies stop or RTT jumps sharply hints at where the trouble starts.