Wrong use of 100.64.0.0/10

Fri Oct 2 15:44:32 UTC 2015

On 2 October 2015 at 16:10, Marco Paesani <marco at paesani.it> wrote:
> Hi Justin,
> I know that we must filter this type of route, but AS9498 (upstream) MUST
> accept only correct networks.
> Or not ?
> Ciao,
> Marco

You are correct.

AS-9730 shoudn't be advertising this range.
AS-9498 shouldn't be accepting this range, and they shouldn't be
advertising it on.
AS-5580 shouldn't be accepting this range, and they shouldn't be
advertising it on.

In fact if we look at LINX as an example, many ASNs are accepting this
route and advertising it on again. Possibly becasue they use the same
filter list for inbound and outbound advertisements so an inbound
mistake just gets echo'ed out to everyone else :(

route-views.linx.routeviews.org> show ip bgp 100.64.0.0/10 longer-prefixes

BGP table version is 0, local router ID is 195.66.225.222

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

              r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

*  100.100.1.0/24   195.66.224.83                          0 5511 9498 9730 ?

*>                  195.66.225.86                          0 34288 9498 9730 i

*                   195.66.224.51                          0 6453 5511
9498 9730 i

*                   195.66.224.53           10             0 8928 5511
9498 9730 ?

*                   195.66.236.35                          0 6067 6453
5511 9498 9730 i

*                   195.66.225.109                         0 41811 9498 9730 ?

*                   195.66.224.153         100             0 6762 5511
9498 9730 ?

*                   195.66.224.118                         0 14537 9498 9730 ?

*                   195.66.224.39                          0 3561 5511
9498 9730 ?

*                   195.66.224.233           0             0 19151 9498 9730 ?

*                   195.66.224.175           1             0 13030 9498 9730 ?

*                   195.66.236.175           1             0 13030 9498 9730 ?

Cheers,
James.