1::1/128 + 2::2/128 - GRH Anomalies Delta (2012-08-17)

Jeroen Massar jeroen at unfix.org
Fri Aug 17 12:57:09 CEST 2012

On 2012-08-17 12:41, Daniel Roesen wrote:
> Hi Jeroen,
> On Fri, Aug 17, 2012 at 11:57:51AM +0200, Jeroen Massar wrote:
>> /128's.... and in non 2000::/3 space? Really!?
>>  ::/0                     Default Route
>> +1::1/128                 Unallocated prefix
>> +2::2/128                 Unallocated prefix
>>  64:ff9b::/96             Unallocated prefix
>>  2000::/3                 Default Route
> The problem with GRH is that people tend to send unfiltered IBGP to it
> instead of a properly filtered EBGP stream. Thus GRH sees all kind of
> more-specific/internal junk that noone else will see, resulting in
> "false positives".

While that is true, 1::1 and 2::2 should never exist anywhere, they are
outside of 2000::/3 and thus are not defined and thus should not be used
and definitely never ever be routed on the Internet. Same for that silly
64:ff9b::/96 prefix.

> To me, this report will only have a real meaning when all GRH peers are
> only sending an EBGP feed which they would also send a downstream BGP
> customer. Unfortunately, that's largely not the case so I stopped
> looking at the report a looong time ago.

That is true.

Maybe it is time to request peers to send prefixes in a certain way indeed.

We could also request people to send certain communities and instruct
GRH to ignore prefixes with certain communities for some reports.

Any proposals there?


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