Simple/best tool to verify PMTUD?

Wed Dec 19 09:37:30 UTC 2012

Hi,

On Dec 18, 2012, at 7:59 PM, Christopher J. Pilkington <cjp at 0x1.net> wrote:

> I'm looking for a simple tool to verify PMTUD is usable along a
> particular path. Ideally this tool would be cross-platform, or run on
> Linux or Windows.
> 
> I've done some testing of my own by hand, but hoping a tool would help
> the admin on the other side be able to test for themselves.

Scamper is a really cool tool, look at this example: 

job at Alice:~$ sudo scamper -c 'trace -P UDP-paris -M' -i 8.8.4.4 2001:67c:208c:10::1
traceroute from 2a02:d28:666::69 to 2001:67c:208c:10::1
 1  2a02:d28:666::1  0.247 ms [mtu: 1500]
 2  2a02:d28:5580:666::a  1.085 ms [mtu: 1500]
 3  2a02:d28:5580:1::31  7.141 ms [mtu: 1500]
 4  2a02:d28:5580:1::21  6.588 ms [mtu: 1500]
 5  2a02:d28:5580::1:411  6.815 ms [mtu: 1500]
 6  2001:7f8:1::a501:2414:2  7.612 ms [mtu: 1500]
 7  2001:9e0:0:2::2  9.793 ms [mtu: 1500]
 8  2001:9e0:0:3::2  8.277 ms [mtu: 1500]
 9  2001:9e0:0:9::2  8.851 ms [mtu: 1500]
10  2001:9e0:411:1::10  9.015 ms [mtu: 1500]
11  2001:67c:208c:10::1  20.220 ms [mtu: 1464]
traceroute from 78.152.42.69 to 8.8.4.4
 1  78.152.42.65  0.230 ms [mtu: 1500]
 2  78.152.42.1  0.253 ms [mtu: 1500]
 3  78.152.44.89  6.693 ms [mtu: 1500]
 4  78.152.34.14  6.906 ms [mtu: 1500]
 5  78.152.44.95  6.705 ms [mtu: 1500]
 6  195.69.144.247  7.207 ms [mtu: 1500]
 7  209.85.248.116  7.183 ms [mtu: 1500]
 8  209.85.255.60  7.416 ms [mtu: 1500]
 9  216.239.49.28  12.922 ms [mtu: 1500]
10  *
11  8.8.4.4  10.481 ms [mtu: 1500]
job at Alice:~$ 

Kind regards,

Job