[outages] Level3 Chicago

'Jeremy Chadwick' outages at jdc.parodius.com
Wed Aug 19 11:07:24 EDT 2009


That's an excellent question -- and one I've always wondered myself.

This is purely speculative, but I believe outbound ICMP (e.g. sent from
the router to whatever src solicited it) is what's de-prioritised.

Someone more familiar with Cisco and Juniper equipment might know for
certain.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |

On Wed, Aug 19, 2009 at 09:55:40AM -0500, Frank Bulk - iName.com wrote:
> Good point.  Is the ICMP rate-limiting of these largish routers ingress and
> egress, or only ingress-only?
> 
> Frank
> 
> -----Original Message-----
> From: outages-bounces at outages.org [mailto:outages-bounces at outages.org] On
> Behalf Of Jeremy Chadwick
> Sent: Wednesday, August 19, 2009 12:21 AM
> To: outages at outages.org
> Subject: Re: [outages] Level3 Chicago
> 
> The closest thing I know of is PingPlotter for Windows.
> 
> I'll remind folks that TCP and UDP-based traceroute/mtr-like utilities
> still rely on ICMP time exceeded (type 11) being sent out to obtain the
> present path, so if folks are looking for a pure TCP or UDP-based
> traceroute or equivalent, to avoid dropping of ICMP, they're barking up
> the wrong tree.  :-)
> 
> -- 
> | Jeremy Chadwick                                   jdc at parodius.com |
> | Parodius Networking                       http://www.parodius.com/ |
> | UNIX Systems Administrator                  Mountain View, CA, USA |
> | Making life hard for others since 1977.              PGP: 4BD6C0CB |
> 
> On Tue, Aug 18, 2009 at 10:42:14PM -0500, Frank Bulk wrote:
> > Is there version of mtr that include support for TCP or UDP types?  A
> google
> > search didn't reveal anything to me, but would be the best of mtr with the
> > benefits of tcptraceroute.
> > 
> > Frank
> > 
> > -----Original Message-----
> > From: outages-bounces at outages.org [mailto:outages-bounces at outages.org] On
> > Behalf Of Jeremy Chadwick
> > Sent: Tuesday, August 18, 2009 12:50 PM
> > To: outages at outages.org
> > Subject: Re: [outages] Level3 Chicago
> > 
> > It would be helpful if you could use something like mtr instead of
> > traceroute in this case.  The below trace could be indicating ICMP
> > de-prioritisation on L3 routers, which is known to be enabled, but could
> > also be an indicator of packet loss starting at hop #5 and "trickling
> > down" through succeeding hops (possibly #10 or #11).
> > 
> > mtr --order=LSRNABW can help in diagnosing this.
> > 
> > -- 
> > | Jeremy Chadwick                                   jdc at parodius.com |
> > | Parodius Networking                       http://www.parodius.com/ |
> > | UNIX Systems Administrator                  Mountain View, CA, USA |
> > | Making life hard for others since 1977.              PGP: 4BD6C0CB |
> > 
> > On Tue, Aug 18, 2009 at 01:36:58PM -0400, Clayton Zekelman wrote:
> > > 
> > > Further to the issue below - I'm typically seeing packet loss at hop
> > > 5.  This particular trace doesn't show it though, although there are
> > > timeouts on hop 6.
> > > 
> > >   1 br0.win.mnsi.net (216.8.137.193) 0 msec 0 msec 0 msec
> > >   2 ge-6-12-222.car2.Detroit1.Level3.net (64.152.144.77) 0 msec 4 msec 0
> > msec
> > >   3 ae-11-11.car1.Detroit1.Level3.net (4.69.133.245) 4 msec 0 msec 4
> msec
> > >   4 ae-8-8.ebr2.Chicago1.Level3.net (4.69.133.242) 8 msec 4 msec 16 msec
> > >   5 ae-5.ebr2.Chicago2.Level3.net (4.69.140.194) 8 msec 8 msec 8 msec
> > >   6  *  *
> > >     ae-2-2.ebr2.Washington1.Level3.net (4.69.132.70) 32 msec
> > >   7 ae-72-72.csw2.Washington1.Level3.net (4.69.134.150) 36 msec
> > >     ae-82-82.csw3.Washington1.Level3.net (4.69.134.154) 36 msec
> > >     ae-72-72.csw2.Washington1.Level3.net (4.69.134.150) 32 msec
> > >   8 ae-2-79.edge2.Washington4.Level3.net (4.68.17.83) 28 msec
> > >     ae-3-89.edge2.Washington4.Level3.net (4.68.17.147) 40 msec
> > >     ae-1-69.edge2.Washington4.Level3.net (4.68.17.19) 24 msec
> > >   9 savvis-level3-te.Washington1.Level3.net (4.68.110.102) 32 msec
> > > 28 msec 40 msec
> > >  10  *  *  *
> > >  11 cr1-bundle-pos1.NewYork.savvis.net (204.70.196.137) 28 msec *  28
> msec
> > >  12 206.24.199.2 48 msec 32 msec 32 msec
> > >  13 toroonnldr01.bb.telus.com (154.11.6.71) 32 msec 192 msec 36 msec
> > >  14 host82.145.115.209.in-addr.arpa (209.115.145.82) 40 msec 40 msec 40
> > msec
> > >  15 209.202.116.58 40 msec 48 msec 36 msec
> > >  16 www.govital.net (209.202.88.24) 36 msec 40 msec 36 msec
> > > 
> > > 
> > > At 01:05 PM 8/18/2009, Clayton Zekelman wrote:
> > > 
> > > >I'm seeing some minor packet loss traversing Level3 in Chicago.
> > > >
> > > >We connect to their network in Detroit, and we're clean until the
> > > >first hop into Chicago.
> > > >
> > > >Anyone else seeing anything like that?
> > > >
> > > >
> > > >
> > > >---
> > > >Clayton Zekelman
> > > >Managed Network Systems Inc. (MNSi)
> > > >344-300 Tecumseh Rd. E.
> > > >Windsor, Ontario
> > > >N8X 5E8
> > > >
> > > >tel. 519-985-8410
> > > >fax. 519-985-8409
> > > >
> > > >_______________________________________________
> > > >outages mailing list
> > > >outages at outages.org
> > > >https://puck.nether.net/mailman/listinfo/outages
> > > >
> > > >
> > > >No virus found in this incoming message.
> > > >Checked by AVG - www.avg.com
> > > >Version: 8.5.409 / Virus Database: 270.13.60/2311 - Release Date:
> > > >08/18/09 06:03:00
> > > 
> > > ---
> > > Clayton Zekelman
> > > Managed Network Systems Inc. (MNSi)
> > > 344-300 Tecumseh Rd. E.
> > > Windsor, Ontario
> > > N8X 5E8
> > > 
> > > tel. 519-985-8410
> > > fax. 519-985-8409
> > > 
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