[outages] Level3 Routing...

[Jeremy Chadwick]

On Fri, Feb 28, 2014 at 11:51:41PM -0500, Jay Ashworth wrote:
> ----- Original Message -----
> > From: "Jeremy Chadwick" <jdc at koitsu.org>
> 
> > However, as I've stated repeatedly [like a broken record], a
> > traceroute/mtr from point A to B is only half the picture -- you need
> > the same from point B to A, due to asymmetrical routing being
> > commonplace.
> 
> We say this a lot, but no one's ever explained to me how you're supposed
> to break into the apache server at the other end to run the reverse trace.
> 
> 1/2 :-)

You must have access to both ends (A and B).  If you don't, correct, all
you can provide is half the picture.  Transport/peering providers will
often stall you (or flat out reject you) if you've only half.  It's just
another excuse in the long list of things network providers can use to
avoid investigating a problem.

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