mtr Often times, troublesome networks won’t show up in the results of a few packets. mtr combines the functionality of the traceroute and ping utils and enables user to constantly poll a remote server to see the latency and performance changes over time. It’s not installed by default on most linux systems, simply get it from the distribution and package manager of choice: $ sudo apt-get install mtr To debug remotely over ssh where no GUI is available, use the --curses or -t option:

This post extends the discussion on traceroute in previous post Traceroute, Firewalls & Geo-IP, and focused on intepreting the traceroute report. Output format explanation: v--- the router/ip-addr traversed by the packet [Hop] [Hostname/(IP-addr)] [RTT1] [RTT2] [RTT3] ^--- transit no. of the route ^---- round-trip time The round-trip time (RTT) is the latency (delay between sending the packet and getting the response). By default, traceroute sends 3 packets per TTL increment.

Table of Contents Traceroute ICMP mode UDP mode TCP mode Output format explanation Hping3 InTrace Nmap: traceroute-geolocation script Traceroute Traceroute is useful for diagnosing networking problems, e.g., end-to-end connectivty, complement with ping. It can also be used to pinpoint the location of devices, routers and firewalls. The tracerouting tools fundamentally rely on the IP packet’s field - TTL (Time-To-Live, decremented at each hop, dies at 0), they send short-life IP packets and wait for Time Exceeded ICMP packets reporting the death of these packets from a router, consequently reveal the route.