Re: Katrina Network Damage Report

[Randy Bush <randy () psg com>]

Re: From: Todd Underwood <todd () renesys com>

to quote bobby dylan "you don't need a weatherman to know which
way the wind blows."  i.e., unless you were the president, the
department of fatherland security, or fema, you probably knew
there was a major disaster ongoing in nola and surrounds.  if
you could read the newpapers, you could even have known of it
in advance.

but, the geolocation stuff is cool.  could it have told us, in
an operationally useful/timely manner, that at&t had moved from
new jersey to spain the other day?

> 1) the multi-hop issue is bogus, i believe.  i'll ignore it
> unless randy chooses to say what he means here.

maybe use <http://nanog.org/mtg-0210/wang.html>.  some siteseer
entries seem a bit mangled, but [0] seems ok.

> 2) yes, indeed.  we chose only to comment on changes in the
> routing table as changes in the routing table.  inferences
> about unreachability of end interfaces is left entirely to
> the reader

but reachability is what it's all about.  the folk here are
paid to deliver packets.  the control plane (routing) is one of
the tools we use to achieve that end.

Re: From: George William Herbert <gherbert () retro com>
> Looking at the routing tables you see failures.  If a prefix
> goes away completely and utterly, and is truly unreachable,
> then anyone trying to see it is going to see an outage.

not if a covering or more specific tells us how to get packets
to the destination.  but perhaps that's what you mean by a
prefix being unreachable and i am being too picky.

randy

---

[0] - bibtex
@inproceedings{ wang02observation,
  Author = "Lan Wang and Xiaoliang Zhao and Dan Pei and Randy Bush and Daniel Massey and Allison Mankin and S. Felix Wu 
and Lixia Zhang",
  Title = "Observation and Analysis of BGP Behavior Under Stress",
  BookTitle = "Proc. of ACM SIGCOMM Internet Measurement Workshop 2002, Marseille, France",
  Month= "Nov",
  Year = "2002",
  url = "citeseer.ist.psu.edu/article/wang02observation.html" }