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Re: level3.net in Chicago - high packet loss?!?

daemon@ATHENA.MIT.EDU (Joe Maimon)
Tue Sep 6 10:35:34 2005

Date: Tue, 06 Sep 2005 10:35:03 -0400
From: Joe Maimon <jmaimon@ttec.com>
To: nanog <nanog@merit.edu>
In-Reply-To: <38D1AE7F-52FA-4BCF-A32F-CF40FA958DC6@gmail.com>
Errors-To: owner-nanog@merit.edu


If the hop(s) following the one you see loss for shows no loss, then 
disregard the loss for that hop, obviously whatever it is, it does not 
affect transit, which is what you really want to know.

Is that correct?


Network Fortius wrote:
> 
> And how exactly would you interpret the number returned by net_loss  
> (int), in a column called "LOSS", in reference to reachability of a  
> "hop" between two end points:
> 
> int net_loss(int at)
> {
>   if ((host[at].xmit - host[at].transit) == 0)
>     return 0;
>   /* times extra 1000 */
>   return 1000*(100 - (100.0 * host[at].returned / (host[at].xmit -  
> host[at].transit)) );
> } ?
> 
> Thanks,
> Stef
> Network Fortius, LLC
> 
> 
> On Sep 6, 2005, at 7:45 AM, Robert E.Seastrom wrote:
> 
>>
>> Network Fortius <netfortius@gmail.com> writes:
>>
>>
>>> Anybody having any idea why such a high packet loss on lever3's
>>> network, in Chicago?
>>>
>>
>> End-user misinterpreting output from MTR.  This network does not
>> appear to have any packet loss end-to-end.
>>
>>                                         ---Rob
>>
>>
>>
>>> Stef:~ scm$ mtr -r www.yahoo.com
>>> ...
>>> tbr1-p010802.cgcil.ip.att.net             0%    16   16   15.12
>>> 24.21   49.26
>>> ggr2-p310.cgcil.ip.att.net                0%    16   16   13.18
>>> 42.66  118.99
>>> so-1-1-0.edge1.chicago1.level3.net        0%    16   16   14.48
>>> 35.84  126.48
>>> so-2-1-0.bbr1.chicago1.level3.net        63%     6   16   14.44
>>> 43.74   79.97
>>>                                                                     
>>> ^^^^^^^
>>> as-1-0.bbr2.sanjose1.level3.net           0%    16   16   61.95
>>> 80.64  176.01
>>> ge-10-2.ipcolo3.sanjose1.level3.net       0%    16   16   63.37
>>> 95.61  148.46
>>> unknown.level3.net                        0%    16   16   63.34
>>> 86.46  168.62
>>> unknown-66-218-82-217.yahoo.com           0%    16   16   62.09
>>> 88.91  127.58
>>> p4.www.scd.yahoo.com                      0%    16   16   64.51
>>> 89.96  183.79
>>>
>>> TIA,
>>> Stef
>>> Network Fortius, LLC
>>
>>
> 
> 

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