[CentOS] OT: centos.org web site not responding

Fri Mar 20 17:50:04 UTC 2009
John R Pierce <pierce at hogranch.com>

Rainer Duffner wrote:
> srv3# mtr -c 10 -r centos.org
> HOST: srv3.ultra-secure.de        Loss%   Snt   Last   Avg  Best  Wrst StDev
> ...
>   7. ae-92-92.csw4.Washington1.Le  0.0%    10   98.6 102.3  97.0 110.3   5.0
>   8. ae-91-91.ebr1.Washington1.Le 50.0%    10  101.8 103.6  98.6 109.8   4.1
>   9. ae-2.ebr3.Atlanta2.Level3.ne 30.0%    10  115.2 118.9 114.1 124.7   4.4
>  10. ae-7.ebr3.Dallas1.Level3.net 20.0%    10  132.4 135.5 130.9 142.2   4.7
>  11. ae-73-73.csw2.Dallas1.Level3  0.0%    10  143.9 137.7 131.2 143.9   4.9
> ...
> So, from this point of view, L3 seems to be losing some packets.
>   



'lost packets' on traces from intermediate hops aren't significant, as 
most routers treat PING as a low priority and if they are busy doing 
their primary routing job, they'll ignore some percentage of pings.

traceroute and its ilk are very inexact tools.     your MTR command, run 
from a San Jose, California machine, gives...

# mtr -c 10 -r centos.org
XXXXXXXXX.com                     Snt: 10    Loss%  Last   Avg  Best  
Wrst StDev
ge-0-0-1-414.er2.sjc1.got.net                 0.0%   2.5  22.0   2.5 
191.4  59.5
ge-1-0-10.cr1.sjc1.got.net                    0.0%  22.2  22.2  14.5  
30.0   5.6
173.ge-1-3-0.mpr1.sjc2.us.above.net           0.0%   3.9  12.0   3.0  
48.5  17.0
xe-1-1-0.er1.sjc7.us.above.net                0.0%   5.5   4.9   3.4   
7.0   1.2
above-level3.sjc7.us.above.net                0.0%  66.3  11.1   3.2  
66.3  19.5
vlan69.csw1.SanJose1.Level3.net               0.0%   7.6   9.7   4.5  
17.0   4.2
ae-63-63.ebr3.SanJose1.Level3.net             0.0%  17.8  13.8   6.5  
30.4   7.6
ae-2.ebr3.LosAngeles1.Level3.net              0.0%  23.6  18.1  12.5  
25.4   5.2
ae-83-83.csw3.LosAngeles1.Level3.net          0.0%  24.4  20.3  13.3  
25.3   4.9
ae-82-82.ebr2.LosAngeles1.Level3.net         10.0%  24.8  21.8  14.9  
26.2   4.1
ae-3.ebr3.Dallas1.Level3.net                 20.0%  47.6  48.8  46.7  
56.1   3.0
ae-73-73.csw2.Dallas1.Level3.net              0.0%  46.1  50.3  46.1  
58.4   4.3
ae-22-79.car2.Dallas1.Level3.net              0.0%  45.9  47.0  45.9  
48.0   0.8
DATABANK-HO.car2.Dallas1.Level3.net           0.0%  47.6  47.4  46.2  
49.0   1.0
ae_cw_10g.databank.com                        0.0%  48.5  47.1  46.7  
48.5   0.6
pod22c_ae.layeredtech.com                     0.0%  46.9  47.5  46.5  
48.2   0.5
???                                          100.0   0.0   0.0   0.0   
0.0   0.0
162.194.232.72.static.reverse.ltdomains.com   0.0%  48.0  47.3  46.4  
48.0   0.4