nanog mailing list archives

Re: Prefix Hijack Tool Comaprision


From: "Josh Karlin" <karlinjf () cs unm edu>
Date: Thu, 13 Nov 2008 17:21:25 -0700

Agreed.  The Internet Alert Registry ( http://iar.cs.unm.edu ) has switched
from monitoring RIPE and Routeviews to direct connections with our PGBGP
enabled router.  This means the IAR has less data, but immediate response
times.   Some of the prefixes were detected as hijacked by the IAR but most
of the hijacked prefixes never reached the IAR's neighbors.  If anyone would
like to add their feed to the IAR we would appreciate it!

Josh

On Thu, Nov 13, 2008 at 2:31 PM, Mohit Lad <mohitlad () gmail com> wrote:

Sorry for the subject line in the previous message :-)

Since this thread started as comparison of the tools, there are two issues
1. Which BGP feeds the tools use? RIPE, RouteViews, other private feeds.
2. How they decide what to send and what not to send?

In this case, BGPMon detected an event that was not detected by others, and
there might be other hijacks that were local in scope where PHAS or Watchmy
might catch something that BGPMon does not. But that does not make one tool
better than the other, unless this pattern is repeated.
Eventually all tools will catch up with each other on the feeds (or so is
the hope), so the difference will then lie in "the decision of what to send
and what to drop".

Mohit

Date: Thu, 13 Nov 2008 20:27:32 +0000
From: "Alexander Harrowell" <a.harrowell () gmail com>
Subject: Re: Prefix Hijack Tool Comaprision
To: Todd Underwood <todd () renesys com>
Cc: nanog () nanog org

OK. This seems to be a flaw in RIPE RIS, a pity because BGPlay is great.

- original message -
Subject:        Re: Prefix Hijack Tool Comaprision
From:   Todd Underwood <todd () renesys com>
Date:           13/11/2008 8:05 pm

alexander, all,

On Thu, Nov 13, 2008 at 07:56:26PM +0000, Alexander Harrowell wrote:
It may be the North American NOG, but it's been said before that it
functions as a GNOG, G for Global. I don't think Brazil is
insignificant. I respect Todd's work greatly, but I think he's wrong
on this point.

you misread me.

i did not say that brazil was insignificant. it's not.  it has some of
the fastest growing internet in latin america.

i said that *this* hijacking took place in an insignificant corner of
the internet.  i mean this AS-map wise rather than geographically.
this hijacking didn't even spread beyond one or two ASes, one of whom
just happened to be a RIPE RIS peer.

real hijackings leak into dozens or hundreds or thousands of ASNs.
they spread far and wide.  that's why people carry them out, when they
do.  this one was stopped in its tracks in a very small portion of one
corner of the AS graph.

as such, i don't count it as a hijacking or leak of any great
significance and wouldn't want to alert anyone about it.  that's why i
recommend that prefix hijacking detection systems do thresholding of
peers to prevent a single, rogue, unrepresentative peer from reporting
a hijacking when none is really happening.  others may have a
different approach, but without thresholding prefix alert systems can
be noisy and more trouble than they are worth.

sorry if it appears that i was denegrating .br .  i was not.

t.

--
_____________________________________________________________________
todd underwood                                 +1 603 643 9300 x101
renesys corporation
todd () renesys com
http://www.renesys.com/blog







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