[clug] how to use traceroute

Bob Edwards Robert.Edwards at anu.edu.au
Tue Jun 24 18:09:46 MDT 2014

On 25/06/14 09:31, Eyal Lebedinsky wrote:
> I used it before to see what is going on with routing. However, there is
> something going
> on with iinet recently, and a download test from ftp.iinet.net.au ran at
> around 50k/s for
> a line sync of 6-7Mb/s.
> I did a 'traceroute ftp.iinet.net.au' and it went all the way to 30
> hops. I added '-m 255'
> and it still went all the way. Looks like some kind of loop between
> (ftp.iinet...)
> and (no DNS). It is still doing this now.
> I find this unusual but maybe I do not understand how it works and why
> this is acceptable.
> Can anyone explain why this is so and is this normal?
> --
> Eyal Lebedinsky (eyal at eyal.emu.id.au)

traceroute is less useful these days as the low TTLs can be detected and
the resulting ICMP messages not returned by many routers.

You may fare a bit better with tcptraceroute and using the default port
80 (everyone lets tcp/80 through...). But the short TTLs can still be
detected by the routers and the ICMP layer may not respond.


Bob Edwards.

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