ipmp_ping, ipmp_pathchar:
Userland tools for querying IPMP-enabled routers.



    General info
    """"""""""""

Both of these tools generate IPMP echo requests, to be passed on
through your network and collect IPMP Path Records on their way. And
be changed into replies. And come back. For this to work, your
routers have to support IPMP.  See Matthew Luckie's thesis below or
have a look at my IPMP element for the Click Modular Router software
framework:

http://github.com/hacklschorsch/click-packages/tree/ipmp

If you don't already know about Click, I strongly suggest to have
a look at it, it's a great piece of software; But running it only
for IPMP is maybe a tad overkill.

Most of this work is (c) Matthew Luckie and Anthony McGregor.
I (Florian Sesser, TUM) merely made both of the tools work for
recent Linux distributions in the course of my thesis (to help me
compare routing protocols in WLAN meshes). 

For information on IPMP, see Matthew Luckie's excellent thesis at
http://www.wand.net.nz/~mluckie/pubs/mluckie-thesis.pdf .



    Usage
    """""

I merely fixed the #ifdef path that was of concern for my platform;
Maybe you need to fix the source some more if you do not use
Linux 2.6.

IMPORTANT: See the command line below. Both utilities only work for
me using the -4 and -R switches and when specifying a size for the
packets (-s ...).



    Examples
    """"""""

Here is some example output from the ipmp_ping tool, host 10.20.1.9
IPMP pinging 10.20.5.9. The right-most number is the flow counter;
The last hop (4->5) lost one probe. Second-most to the right is the
time stamp in µs precision. (IPMP supports nanosecond precision,
but our router platform does not). As you can see, this link is
asymmetric, having only two hops on its reverse path.

# ipmp_ping -4 -R  -s 1200 10.20.05.09 -t 1 -c 1000
---------------------------------------------------------------
[...]
> * 0   127.0.0.1  Oct  8 16:14:11 2010 367233000 0
>   1  10.20.4.33  Oct  8 16:14:11 2010 370650000 7
>   2   10.20.4.9  Oct  8 16:14:11 2010 372399000 7
> * 3   10.20.5.9  Oct  8 16:14:11 2010 373934000 7
>   4  10.20.4.33  Oct  8 16:14:11 2010 375663000 7
> * 5   10.20.1.9  Oct  8 16:14:11 2010 378716000 6
> forward path = 3 hops, reverse path = 2 hops
> rtt: 11ms
[...] 
---------------------------------------------------------------


This is sample output from the ipmp_pathchar tool, which uses IPMP
and a PacketPair technique to infer link bandwidth. Unfortunately,
this technique does not work well on wireless (especially multi-hop)
networks, for various reasons.
(Actually, ipmp_pathchar uses ncurses and is interactive. This is
a textual screenshot, if you will.)

# ipmp_pathchar  -4 -R -s 1200 10.20.05.09
---------------------------------------------------------------
> ipmp_pathchar 10.20.05.09: minsize 108, maxsize 1200, tx/rx
> 144/129, paths 1     127.0.0.1 -> 10.20.4.33 : 2394 kbps [min 437
> max 7131]
> 10.20.4.33 ->  10.20.4.9 : 5560 kbps [min 4927 max 140903]
>  10.20.4.9 ->  10.20.5.9 : 9972 kbps [min 859 max 30545]
>  10.20.5.9 -> 10.20.4.33 : 2532 kbps [min 985 max 22285]
> 10.20.4.33 ->  10.20.1.9 : 6938 kbps [min 2591 max 26234] 
---------------------------------------------------------------



    Copyright
    """""""""

I publish my additions and/or changes under the respective
licenses of the original work, to avoid trouble and because I
do not care much. In this case, it is BSD. See the source files
for more information.


    Greetings
    """""""""

All the best to Matthew Luckie, who provided me this code and
tirelessly answered my stupid questions.

Finally, I'd be glad if any of this is useful to you!

Florian Sesser <sesser@in.tum.de> 2010