[lug] hping for path MTU discovery?

[Andrew Diederich]

On 5/11/06, David L. Anselmi <anselmi at anselmi.us> wrote:
<snip>
> You might like tracepath better.

That's a good looking tool -- I haven't used it before.  I'm also
looking for a way to test point-to-point PMTU.  Ping seems to do the
best so far as I learn more.  I'm trying things like this:
ping -M do -s 1472 example.com

-M do sets the DF (don't defragment) header, -s sets the size of the
packet.  Anything over 1472 and I run into problems with the local box
going over the 1500 local MTU max.  I do a packet capture like:
sudo tcpdump -w myfile -s 2000 host example.com
And then read that file with ethereal, because I'm lazy.

I haven't found any problems with PMTU yet, but that may because I'm
only able to send a file equal to or lower of the routers from one end
to the other.

-- 
Andrew Diederich