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

[John Fraizer]

On Mon, 8 Sep 2003, Gert Doering wrote:

> Hi,
> 
> On Mon, Sep 08, 2003 at 08:48:55AM -0400, John Fraizer wrote:
> > 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)
> 

In this case, I would recommend that the ISP do something along the lines
of:

RX the anycast prefix, strip the "no-export" from it, tag it with an
internal community that causes it to be announced ONLY to BGP full-routes
customers TAGGED no-export.

Another "fix" would be to simply have the customer static route for that
prefix.  It's not as nice but, it would make it work.


--
John Fraizer
EnterZone, Inc 
(13944+$|13944+_14813+$|13944+_17266+$)
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