mailing list archives
Re: Disaster recovery using as-prepend?
From: Todd Vierling <tv () duh org>
Date: Fri, 17 Feb 2006 15:55:47 -0500 (Eastern Standard Time)
On Thu, 16 Feb 2006, Warren Kumari wrote:
If your primary is connected to ISP_A and the backup is connected to ISP_B,
customers connected to ISP_B MAY still flow to your backup DC (ISP_B will
probably set local preference on all customer routes - you should be able to
override this behavior with communities but not all providers support this (or
honor it 100% of the time!))
And in addition to that, even multihomed customers of ISP_B may choose the
prepended route for a number of different reasons; for instance, ISP_B might
be a cheaper pipe for them, or there may be a smart-ish routing device or
scheme in play that overrides normal BGP decision making.
-- Todd Vierling <tv () duh org> <tv () pobox com> <todd () vierling name>