[6bone] non-global address space for IXs (was: 2001:478:: as /48)

[Gert Doering]

Hi,

On Mon, Sep 08, 2003 at 08:48:55AM -0400, John Fraizer wrote:
> In the case of opentransit not stripping it so they can "show it" to their
> customers, they don't need to show it to their customers.  If it's an
> anycast prefix thats being used, and their customer tries to go to that
> anycast address, once the traffic makes it onto OT's network - they're
> going to send it to the closest one.  They don't need to leak the
> "no-export" tagged routes to make that work.

It's not that easy.  In the case of downstream BGP customers that do not
have a default-route, you can run into the interesting case of "both
upstreams have the anycast prefix in their table, neither is sending
it to this customer (due to no-export) and thus the prefix is not
visible *at all* by the customer".

ISPs with BGP "full table, please" customers shouldn't suppress prefixes
unless there's really good reason for it.

(Note that I'm not talking about peers, or "partial route" customers, or
whatever else might be around)

Gert Doering
        -- NetMaster
-- 
Total number of prefixes smaller than registry allocations:  55575  (56535)

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