[outages] Chicago-area Level3 to Amazon AWS EAST-1

Jeremy Chadwick jdc at koitsu.org
Thu Sep 27 15:05:51 EDT 2012


George,

For the future: you need to provide traceroutes from both directions.
Most routing these days is asymmetric.  Heavily covered here:

http://www.nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N47_Sun.pdf

But now that you've "re-routed traffic" (I assume you simply denounced
and de-peered with your AS3356 peering point?  Or did you physically
down an interface?), the reverse-path traceroute (from 75.101.163.221 to
wherever you did the original TCP ping from) won't necessarily be the
same as when you were being impacted.

TL;DR -- always provide traceroutes from both directions, and always
perform this *before* making any routing/peering changes.

-- 
| Jeremy Chadwick                                   jdc at koitsu.org |
| UNIX Systems Administrator                http://jdc.koitsu.org/ |
| Mountain View, CA, US                                            |
| Making life hard for others since 1977.             PGP 4BD6C0CB |

On Thu, Sep 27, 2012 at 06:50:34PM +0000, Sarlas, George wrote:
> Since approx. 4am CT, we've been seeing 15-30% dropped packets for traffic going from our Chicago Level3 connection to Amazon's EAST-1 data center.  Our San Francisco office (also using Level3) isn't experiencing a problem.  I've re-routed this traffic to our backup Internet connection (Airlogic) for now, and that traffic is getting through just fine.  Anyone else seeing this problem?  Ticket already opened with Level3, waiting to hear back.  Thank you.
> 
> Here's the route my traffic is taking (time outs at the bottom are normal, ICMP gets blocked from that point on).
> 
> 
> 
> 
> 
> Tracing route to zioreports.com [75.101.163.221]
> 
> over a maximum of 30 hops:
> 
> 
> 
>   1     1 ms     1 ms     1 ms  ge-6-2-107.car4.Chicago1.Level3.net [4.71.102.161]
> 
>   2     *        *        *     Request timed out.
> 
>   3    16 ms    22 ms    25 ms  ae-5-5.ebr2.Chicago2.Level3.net [4.69.140.194]
> 
>   4    19 ms    24 ms    25 ms  ae-6-6.ebr2.Washington12.Level3.net [4.69.148.145]
> 
>   5     *        *        *     Request timed out.
> 
>   6    16 ms    18 ms    23 ms  ae-82-82.csw3.Washington1.Level3.net [4.69.134.154]
> 
>   7    16 ms    16 ms    17 ms  ae-3-80.edge2.Washington1.Level3.net [4.69.149.142]
> 
>   8    17 ms    17 ms    16 ms  AMAZON.COM.edge2.Washington1.Level3.net [4.79.22.74]
> 
>  9     *        *        *     Request timed out.
> 
> 10    17 ms    18 ms    17 ms  72.21.222.139
> 
> 11    18 ms    18 ms    18 ms  216.182.224.17
> 
> 12     *        *        *     Request timed out.
> 
> 13     *        *        *     Request timed out.
> 
> 14     *        *        *     Request timed out.
> 
> 15     *        *        *     Request timed out.
> 
> 16     *        *        *     Request timed out.
> 
> 17     *        *        *     Request timed out.
> 
> 18     *        *     ^C
> 
> 
> Here are the results of a TCPing to port 443:
> 
> 
> 2012:09:27 09:50:02 Probing 75.101.163.221:443/tcp - Port is open - time=20.926ms
> 
> 2012:09:27 09:50:03 Probing 75.101.163.221:443/tcp - Port is open - time=31.168ms
> 
> 2012:09:27 09:50:05 Probing 75.101.163.221:443/tcp - Socket is not connected (10057) - time=2012.341ms
> 
> 2012:09:27 09:50:07 Probing 75.101.163.221:443/tcp - Port is open - time=31.358ms
> 
> 2012:09:27 09:50:08 Probing 75.101.163.221:443/tcp - Socket is not connected (10057) - time=2012.448ms
> 
> 2012:09:27 09:50:10 Probing 75.101.163.221:443/tcp - Port is open - time=30.985ms
> 
> 2012:09:27 09:50:12 Probing 75.101.163.221:443/tcp - Port is open - time=31.224ms
> 
> 2012:09:27 09:50:13 Probing 75.101.163.221:443/tcp - Port is open - time=32.065ms
> 
> 2012:09:27 09:50:15 Probing 75.101.163.221:443/tcp - Socket is not connected (10057) - time=2012.375ms
> 
> 2012:09:27 09:50:17 Probing 75.101.163.221:443/tcp - Port is open - time=31.115ms
> 
> Ping statistics for 75.101.163.221:443
> 
>      10 probes sent.
> 
>      7 successful, 3 failed.
> 
> Approximate trip times in milli-seconds (successful connections only):
>     Minimum = 20.926ms, Maximum = 32.065ms, Average = 20.884ms
> 
> 
> 
> ----
> George Sarlas
> Manager, IT Operations
> iRhythm Technologies, Inc.
> 
> 2 Marriott Dr.
> Lincolnshire, IL 60069
> 
> email: gsarlas at irhythmtech.com
> phone: 224-543-4253
> 

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