Lots of non-existant networks

Curtis Villamizar curtis at brookfield.ans.net
Thu Jun 26 17:17:44 UTC 1997

In message <Pine.SOL.3.95.970618151012.15875A-100000 at roofdog.acsi.net>, "Eric D
. Madison" writes:
> There still seems to be a lot of Routes out there that are not in the
> RADB.  I know that ANS is not excepting routes not in a routing database,
> and others are starting to follow.  It's a good idea!  
> I am not getting some of these routes because of the lack of an RADB
> entry, and it's very frustrating.. 
> Anyone else having the same problems??
> Ohh one more thing.. Seems that there are also some routes that are being
> advertised that don't even have a InterNIC/RIPE/APNIC entry either..
> If they don't have an entry, then they are not real "Valid" routes, so I
> don't want to route them.. but the Origin is from a large
> provider..  any suggestions?  Seems that they have build their whole
> infrastructure on these routes too.
> Eric
> _______________________________________________________
>       Eric D. Madison - Senior Network Engineer -   
>  ACSI - Advanced Data Services - ATM/IP Backbone Group  
>    24 Hour NMC/NOC (800)291-7889 Email: noc at acsi.net

The route-dumps anaylsys page has been updated.  It provides quite a
bit more detail, some ANS specific (sorry).  The URL is:


New stuff on this page are:

  Listing by border AS - so we know who we can bug if a reachability
  problem is reported and we know how much will be missing due to
  filtering on a per border AS basis.  It also helps us concentrate on
  routes passed to us by our direct customers.  This would be useful
  to others if they peer with some of the same border AS.

  Reports now include (as of the most recent one):

    2477 unregistered prefixes 
    240 prefixes unreachable due to incorrect origin AS 
    2 prefixes with no ANS policy
    15 prefixes with incorrect ANS policy

    2074 prefixes registered with incorrect origin AS (a warning)

  Each problem category is also sorted by border AS and origin AS

  Pages are available which report on only a specific border AS and/or
  origin AS.  These are useful to anyone wanting to clean up their own
  AS, since the observed paths for each prefix is provided.

  Information is available down to the prefix, with observed AS paths
  reported, as well as the [sort of encrypted - consider it a bug] ANS
  policy in cases where ANS policy is thought to be the problem.

Of the 22 border AS with any unregistered prefixes (46 with some sort
of problem or warning), the worst offenders are the border AS with
over 90 unregistered prefixes:

  AS174 (149),
  AS286 (94),
  AS568 (166),
  AS701 (550),
  AS1239 (1131),
  AS1800 (443).

There are 398 origin AS with unregistered prefixes, most with just a


btw- the "15 prefixes with incorrect ANS policy" both seem to be due
to a transient where we intentionally do not accept a backup route
from the CIX for certain providers we directly peer with yet the CIX
was announcing one.  The "2 prefixes with no ANS policy" are one
prefix origin AS and we addressed this after the report.

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