Mulroute

Mulroute is a multi destination IPv4/IPv6 traceroute for OS X and Linux. You can specify hosts as operands or write them to the standard input (whitespace separated). Application uses raw sockets so it needs to be run in a privileged mode.

Getting started

These instructions will get you a copy of the project up and running on your local machine.

Prerequisites

You need to have the following installed on your machine:

C++ compiler with C++11 support
pthread library

Installation

First clone this repository and run make:

$  git clone https://github.com/romeritto/mulroute
$  make

An executable file bin/mulroute will be created. You can symlink it into your PATH for an easier invocation.

$  (in the project root directory)
$  sudo ln -sf "$PWD"/bin/mulroute /usr/local/bin

Setting SUID

Note that mulroute as well as other network utilities like ping needs root privilidges. In case of ping, the owner is set to root and the executable's SUID bit is set. This step is optional and you should know what you are doing.

$  chmod u+s ./bin/mulroute
$  sudo chown root ./bin/mulroute

Usage

The usage is very similiar to normal traceroute, but you can specify multiple hosts.

$  sudo mulroute google.com github.com
traceroute to google.com (172.217.16.110), 30 hops max
 1  nbg-416n (192.168.1.1)  1.875 ms  1.748 ms  1.724 ms
 2  10.10.10.1 (10.10.10.1)  2.288 ms  1.992 ms  2.006 ms
 3  192.168.201.65 (192.168.201.65)  3.354 ms  3.202 ms  3.051 ms
 (omitting 8 lines)

traceroute to github.com (192.30.253.112), 30 hops max
 1  nbg-416n (192.168.1.1)  1.790 ms  1.698 ms  1.735 ms
 2  10.10.10.1 (10.10.10.1)  2.131 ms  1.991 ms  2.049 ms
 3  192.168.201.65 (192.168.201.65)  3.355 ms  3.779 ms  3.420 ms
 (omitting 12 lines)

The hosts can be also read from the standard input:

$  sudo mulroute<Enter>
github.com
8.8.8.8
<Ctrl+D to stop the input>

Note that this might be used for tracerouting all hosts specified in a file:

$  sudo mulroute < sample_urls.txt

Options

There are multiple options available. Run sudo mulroute -h to see the description.

$  sudo mulroute -h
usage: mulroute [46nh] [-f start_ttl] [-m max_ttl] [-p nprobes]
          [-z sendwait] [-w waittime] [host...]

Mulroute - multi destination ICMP traceroute. Specify hosts as operands
or write them to the standard input (whitespace separated). Application
uses raw sockets so it needs to be run in a privilidged mode.

Arguments:
  hosts                    Hosts to traceroute. If not provided, read
                           them from stdin.

Options:
  -h                       Show this message and exit
  -4                       If protocol of a host is unknown use IPv4 (default)
  -6                       If protocol of a host is unknown use IPv6
  -n                       Do not resolve IP addresses to their domain names
  -f start_ttl             Start from the start_ttl hop (default is 1)
  -m max_ttl               Set maximum number of hops (default is 30)
  -p nprobes               Set the number of probes per each hop (default is 3)
  -z sendwait              Wait sendwait milliseconds before sending next probe
                           (default is 10)
  -w waittime              Wait at least waittime milliseconds for the
                           last probe response (deafult is 500)

Examples of using the options

$  sudo mulroute -f 8 -m 13 google.com nah.com

Start with packets with TTL 8 and continue up to 13.

$  sudo mulroute -p 1 -n -z 50 rojk.nl slovakia.sk

Send only 1 probe per hop (TTL) and wait at least 50 ms between sending each probe. Also do not resolve IP addresses from received probes to domain names.

Under the hood

The idea behind this traceroute utility is fairly simple. The app uses two threads - one for sending the probes and one for receiving.

Sending

Every probe is an ICMP Echo Request packet which has its ID and SEQ fields set according to the current destination, ttl and probe number.

We start with TTL start_ttl and gradually send the probes with this TTL to every destination.

Receiving

Using a raw socket we receive a copy of every ICMP message sent to the machine. These messages contain 8 bytes of the original payload, which is enough for the original ICMP Echo Request header that was sent. Based on ID and SEQ of this header we match received packet to the probe.

Acknowledgments

I want to thank to Mgr. Martin Mareš, Ph.D. for the idea to make a multitraceroute utility and Adrián Király for giving me a great suggestions.

Contact me

If you find something unclear or if you have a suggestion, do not hesitate to write me an email at r.sobkuliak(at)gmail.com

sobkulir/mulroute