BGP and aggregation

Mon May 13 21:48:29 UTC 2002

In the referenced message, Austin Schutz said:
> 
> On Mon, May 13, 2002 at 06:57:19AM -0400, PS wrote:
> > 
> > Multiple ASNs wouldn't solve anything in this case.  What was wanted was
> > under normal circumstances both A and B only announce a /20, and when the
> > link between A and B breaks announce more specifics.  Multiple ASN =
> > inconsistent AS.. no no.
> > 
> 
> 	Not necessarily. If 'A' originates the aggregate route it can still be
> transited via 'B', though with an additional AS hop. Not a perfect solution,
> but then neither is running a gre tunnel.
> 
> 	Austin

The only perfect solution is having multiple internal paths which are
resilient to simultaneous outage. Failing that, I've never had a problem
with GRE. Back in 1994-1997 or so, I used them a lot for disconnected
sites, much as someone else mentioned, across sprint. Worked great
and was certainly cheaper than interlata circuits.