[clug] how to use traceroute

Eyal Lebedinsky eyal at eyal.emu.id.au
Tue Jun 24 18:15:59 MDT 2014

On 06/25/14 10:09, Bob Edwards wrote:
> 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?
>> TIA
>> --
>> 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.
> Cheers,
> Bob Edwards.

Thanks Bob,

tcptraceroute works and gives the expected results. Live and learn.


Eyal Lebedinsky (eyal at eyal.emu.id.au)

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