Dan Lanciani wrote:
> 
> Andrew White <[EMAIL PROTECTED]> wrote:
> 
> |Dan Lanciani wrote:
> |
> |> There is a huge difference between requiring a /48 and allowing anything
> |> greater than /8.  The former ...
> |> while the latter means that you can bypass the black hole with 2 or 4
> |> route additions.
> |
> |Of course you can bypass it.
> 
> The proposed wording is:
> 
> ``Router manufacturers MUST ensure that said black hole cannot be
> deconfigured, turned off, or otherwise overridden in toto;''
> 
> How do you reconcile this with ``Of course you can bypass it.''?

The immediately preceding context was Alan stating that his reading was that
only /8 routes are to be discarded and that anything more specific would be
forwarded.  You seemed to be saying that having an easy workaround
invalidated the value of the filter, which Alan and Christian (and I) seem
to disagree with.


I object to the proposed wording also, if only because routers must be able
to be configured for 'inside' work at which point local addresses are
in-scope and should not be filtered.  It should be possible to disable the
filtering or refine it.


I agree that the Hinden/Haberman draft only covers filters AT the border,
and that this is a weakness.  All routers designed for BGP routing should by
default discard (preferably with "ICMP No Route To Host" or "ICMP
Destination Unreachable" as appropriate) packets with local source or
destination addresses and BGP implementations should ignore / refuse updates
to such addresses (of any length prefix).  Unless administratively
configured to do otherwise.

With such a restriction, I don't see much incentive for an ISP (or other
user) to disable the filters in a general manner.  Since most routers will
filter anyway, they can only route the local packets to other people who've
disabled the filters, and anyone disabling the filters (and only those
people) needs to cope with potential routing table increases for their OWN
tables.

-- 
Andrew White
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